Viz Mosart is Vizrt's powerful suite of tools for studio automation, production assistance, and advanced graphics control. It enhances consistency and efficiency in live and as-live production, so that even complex shows can be run error-free from a single operator position.

Viz Mosart controls devices flexibly according to templated sets of repeatable actions, automating that control according to stories prepared in a rundown and enabling creative manual interaction whenever needed.

In this document you will find listed all important changes since Viz Mosart 5.16.

Viz Mosart 5.17.0

Release Date: 2026-09-07

Viz Mosart 5.17 adds a Magellan router driver using the LRC+ protocol, and on-air protection for switcher macros, so that cueing the next template no longer disturbs a split screen already on program.

Story Recorder has been through a substantial hardening. Session handling, operator feedback and error messages are now specific about what went wrong, instead of the subsystem failing silently or reporting a generic logging-service error for unrelated problems.

Media Administrator no longer restarts a full clip index when settings are saved, and clip status on large Omneon systems resolves without waiting for the whole catalogue to be indexed.

All Mosart applications now log memory telemetry, giving support the data needed to diagnose memory problems on long-running systems.

Adaptive Live Producer

• Fixed: Several issues in this early preview feature have been resolved: a one-frame background flash when transitioning from a DVE to a graphic, the graphic after a break missing from the preview, and the fullscreen graphic after an opening break not always being taken on air when the rundown is loaded (MOSART-15067, MOSART-15117, MOSART-15154).

• New: A new SET_ALTERNATIVE_CONCEPT control command — also available in the Keyboard Shortcut Editor — changes the alternative concept of a video wall's superchannels on the fly in this early preview feature. The concept is applied to the superchannels of the mixer effect's program and preview walls; graphics already on air are re-taken as hard cuts so the switch happens as fast as possible, and armed graphics are re-armed (MOSART-15018).

• New: A/V Setup has two new video-channel columns, Allocation and Source ID, and the AV Automation settings have a new Dynamic Input Allocation section. These are groundwork for dynamic input allocation with the Adaptive Live Producer and are not yet ready for use. Leave Allocate inputs on demand at its default (off); the feature will be completed in a coming release (MOSART-14956).

Switching

• New: A router driver for Imagine Communications / Grass Valley Magellan routers, using the LRC+ protocol over TCP (default port 52116). Select Magellan as the router driver in AV Setup; crosspoints are then taken from templates as with any other router (MOSART-14670).

• New: On-air protection for switcher macros. A macro recall in a template can now be protected, so that cueing the template does not run its macro while another protected macro template is on program. Previously, cueing a second DVE template visibly rearranged the split screen already on air. The option is set on the macro recall command and has the values off (default), same-type and all. When protection applies, the macro runs at the take instead of at the cue, and the operator is warned. Existing configurations are unaffected (MOSART-14962, MOSART-14757).

Video Clip Playout

Clip Players

EVS

• Fixed: An issue affecting EVS video servers configured in mirror mode with IPDirector (IPD API). If one of the mirrored servers became unavailable, Viz Mosart could no longer cue or play out clips from the remaining server either, failing with a Clip not found error (The previous workaround was to select a salvo containing just the available server) (MOSART-15009). This was first fixed in maintenance release 5.16.1.

Clip Status

• Fixed: Clips in a loaded rundown now resolve directly against the Omneon video server, rather than waiting for the whole clip catalogue to be indexed. On installations with large clip directories, all clips could otherwise show as offline for 20 minutes or more after a restart, and templates that autotake on clip duration fell back to a four second default (MOSART-15007).

• Fixed: Saving Media Administrator settings no longer tears down every clip-server connection and restarts a full clip index. Only the servers whose configuration actually changed are reconnected, and unchanged servers keep their connection and their clip status. Previously any save, including simply turning on verbose logging to investigate a problem, could take every clip in the loaded rundown offline for the length of a complete re-index (MOSART-15025).

Graphics

• Fixed: A fullscreen graphic added to a story after the rundown was loaded was shown as available in the rundown, even though it had not been initialized on the Media Sequencer. Such a graphic is now checkerboarded until the Media Sequencer confirms that the content is loaded (MOSART-14340).

• Improved: The Viz Mosart GUI now shows on-air overlay graphics that were played from another rundown, for example from a keyboard shortcut or the Favorites tab. Previously these were only shown if the graphic also existed in the current rundown (MOSART-14853).

• New: The per-story design parameter from the newsroom MOS object is forwarded to the Media Sequencer playlist entry as a custom attribute, so that Execution Logic can switch the graphic design per story. The field is mapped in newsroomsettings.xml (MOSART-14979).

• Fixed: AE Live fullscreen graphics are now taken out when the next story is taken. Previously the outgoing graphic stayed on air, and on a second pass through the rundown a take on the same layer produced nothing on the output while still being logged as successful (MOSART-15005).

• Fixed: The Take out option in the media pool context menu is no longer offered for graphics that are not lower thirds (MOSART-15022).

• Fixed: The AE Live fallback value for the reset action was PREVIEW where it should be RESET, so clear program did not remove on-air graphics unless the MOS XML stated the action explicitly. A reset action given in the MOS XML still takes precedence (MOSART-15060).

• Improved: The AE Live graphics driver now reports its renderer requests to the instrumentation panel in AV Automation, so playout against the renderer can be followed without reading the log files (MOSART-15061).

• Fixed: The story-start overlay (template type STORYSTART, typically MosartStoryStart) is now taken when the first story of a rundown goes on air, and is no longer triggered — and immediately taken out again — when a rundown is loaded, reloaded or re-cued. Previously the first story of a show never announced its start, while every load and reload produced a spurious story start; both behaviors date back to Viz Mosart 3.8 (MOSART-14953).

Audio

Audio Mixers

• Improved: The Wheatstone audio mixer driver can now send the CUE command in place of PFL for prefade listen, for console models that do not support the PFL command, such as the D8, S4, S2 and Strata. Enable it with the new setting WheatstoneUseCueForPfl in the AudioMixerConfiguration.xml configuration file (MOSART-14550).

• Fixed: Wheatstone audio faders could land on the wrong level when set with a crossfade, including the default of 4 frames — a fader could end up around −15 dB instead of 0 dB while AV Automation and the Audio Panel both showed the correct level. Workaround was to set the crossfade to 0 frames (MOSART-15102).

• Fixed: The Calrec audio mixer driver — which serves both Calrec and SSL audio mixers — could pause for 1.5 seconds when disconnecting, for example when the driver is reloaded or AV Automation shuts down, and then terminate the connection abruptly. The disconnect is now immediate and orderly (MOSART-15099).

• Fixed: When a Calrec audio mixer in an Active-Passive configuration failed over from the Main to the Backup system, AV Automation was left showing a half-connected status and needed a restart to fully recover. It now reconnects automatically and reports a healthy status through failover and fail-back (MOSART-15041).

• Fixed: For the Calrec audio mixer driver, the AckTime and ConWait entries in the shipped AudioMixerCalrec.xml were silently ignored — the driver only read them in lowercase. Both spellings are now accepted. Note that values previously edited without effect will take effect after upgrading, so verify any tuned values on timing-sensitive installations (MOSART-15110).

Audio Players

• New: A setting prevents Viz Mosart from sending a stop command to audio players when connecting and when a rundown is loaded or reloaded. This is intended for installations where an audio player is shared between galleries and a loop has to keep running. The setting is off by default, so current behavior is unchanged (MOSART-15068).

Rundown and Story Handling

• Fixed: In Rehearsal mode, clip availability status was not sent back to MOS-based newsroom systems such as ENPS, so a clip could show as available in the Viz Mosart GUI while the newsroom system still showed it missing. Availability is now reported in Rehearsal mode just as in normal mode (MOSART-14372).

• Fixed: A rundown in READYTOAIR mode could be demoted to not-ready and disappear from the Viz Mosart GUI when it was re-requested from the newsroom system, for example after a reload — sometimes minutes before air. The cause was the ready flag being written as "True" but compared against "true"; it is now written and read consistently, so the rundown stays ready to air (MOSART-14996).

• Fixed: A manual accessory sent from OpenMedia is no longer treated as an automatic accessory when the story item also carries a media object (MOSART-15013).

Story Recorder

• New: An optional confirmation dialog when ending a Story Recorder session, controlled by the new setting storyRecorderConfirmDisable. It is off by default; when enabled, the dialog appears on every path where the operator disables Story Recorder (MOSART-15045).

• Fixed: Story Recorder no longer reports Mosart Server Log Service can not be reached for problems that have nothing to do with the log service. The message now names the actual cause, such as a record port that did not respond. Two underlying faults are also fixed: validation of the recording cleanup folder no longer blocks the enable path when the folder is on an unreachable host, and the Omneon driver no longer attaches its clip-event listener to a channel owned by another system (MOSART-15045).

• Fixed: Session handling has been hardened throughout. A record port stopped from outside during a session is now reported and the session paused, instead of the panel continuing to show Recording; a silent step during enable is ended by a watchdog with a message naming it; disabling and immediately re-enabling no longer drops the enable silently; the panel state is restored after a network interruption or a main/backup failover; and network operations no longer run on the thread that serves the Story Recorder adapter (MOSART-15063).

• Fixed: A set of further defects found during lab testing of the above, including Deliver reporting success regardless of outcome, recordings going to the previous salvo's port after a salvo switch, and Story Recorder settings not applying without a service restart (MOSART-15073).

• Fixed: Saving Story Recorder settings while a session is running now takes effect at the next Story Recorder enable, and the Viz Mosart GUI tells the operator that the save does not affect the running session. Previously such a save was silently ignored until the Mosart Logging Service was restarted. The blanket save warning is replaced by the per-setting guidance, and the settings dialog now tracks changes correctly when a value is changed back or reset (MOSART-15085).

• Fixed: Story Recorder clips rendered by Mimir started and ended progressively earlier the longer a recording ran, on fractional frame rates such as 29.97 and 59.94 fps — about one frame per 33 seconds, which no calibration value could compensate. The exact frame rate is now used, so clips land frame-accurately wherever they fall in the recording (MOSART-15146).

Viz Mosart GUI

• Improved: The Viz Mosart GUI application is now built with full compiler optimizations, which had been unintentionally disabled since Viz Mosart 5.5. This can make the GUI generally more responsive, while crash reports remain as detailed as before (MOSART-15093).

• Fixed: The Rundown Over/Under and Time to Next Break timers showed misleading values when a show ran past its planned duration — Over/Under counted up from -59:59 without turning red, and Time to Next Break counted down from 23:59:59. Past the end of the planned rundown, Over/Under now counts up from 00:00 in red, and Time to Next Break no longer wraps. This applies wherever the timers are shown: the Viz Mosart GUI, the Timing Display application and the Smart Panel’s Timing Display views (MOSART-13751).

• Fixed: Story Recorder control commands are available in the Keyboard Shortcut Editor, with their full list of actions. Previously the command was missing the first time the editor was opened, and had an empty action list afterwards (MOSART-14544).

• Fixed: A prefilled preset dropped onto a keyboard shortcut keeps working after switching to another rundown. Previously the key silently did nothing, while the log still reported the take as successful. Shortcut buttons and Favorites now also show the correct icon for presets and Viz Arc actions (MOSART-15044).

Frame Accuracy

• Fixed: The Viz Plura Diagnostic genlock report now names the PCL PCIe 3G (v2) card, instead of Unknown (0x67), and no longer reports a large negative Total drift for a healthy card — a computation error that also triggered a false Significant drift detected warning contradicting the rest of the report (MOSART-15082, MOSART-15119).

Remote Control Service and API

• Improved: The Swagger documentation for control commands no longer points at a fixed 5.12 version of the Viz Mosart documentation (MOSART-14328).

• Fixed: The Remote Control API Swagger page served by Web Apps generated request URLs without the /mosart path prefix that the proxy requires, so every call made from that page returned 404 (MOSART-14923).

• Fixed: Opening a rundown from a web application through the Remote Control Service's SignalR connection did nothing — the rundown never loaded and no loading status was reported. This had never worked since the capability was added in Viz Mosart 5.10; the equivalent REST API command and opening from the Viz Mosart GUI were unaffected. Opening over SignalR now loads the rundown and reports progress as expected (MOSART-15147).

• Fixed: Since version 5.16.0, every clean disconnect of a web client — each Showmaker page load, for example — logged three error messages with stack traces in the Remote Control Service console although nothing was wrong. A clean disconnect now logs a single informational line, including any reason the client gave (MOSART-15247).

Server Administration

Configuration and Settings

• Improved: Settings that only take effect after restarting an application now say so in their own description, naming the application — for example the Story Recorder clip outputs, which need a restart of the Mosart Logging Service. The Story Recorder save warning no longer asks for a service restart when the changed settings apply at the next Story Recorder enable, and the genlock calibration fields in AV Automation explain what applies live (MOSART-15083).

• Improved: The Genlock and clock-source settings have moved from AV Automation Device Properties into the Viz Mosart Central Settings window, including the calibration latencies, timecode format and genlock statistics. Existing values are migrated automatically on upgrade — previously they were stored per Windows user, so calibration set under one account was invisible under another — and changes now apply at runtime without restarting AV Automation. The old Genlock tab links to the new location (MOSART-15136).

• Improved: The maximum value for the Audio Mixer Command Latency calibration setting is raised from 100 ms to 1000 ms (MOSART-15136).

Logging

• Improved: Verbose logging has been added along the chain that reports graphics content status, to make it possible to diagnose cases where graphics remain checkerboarded in the Viz Mosart GUI although they are loaded on the Media Sequencer (MOSART-14648).

• New: Memory telemetry in Manus Administrator, AV Automation, Media Administrator, Overlay Graphics Interface and the Viz Mosart GUI. Each application writes one log line per minute with its own memory usage together with the machine memory state, and a 32-bit application warns in the log when it approaches its address-space limit. This gives support the data needed to diagnose memory problems on systems with long uptime. Controlled by the new Memory telemetry Manus setting (default on), which applies to all Mosart applications without restarting them (MOSART-15059).

Security

There are no security changes in Viz Mosart 5.17. The authentication and device-trust capabilities introduced in Viz Mosart 5.15 and 5.16 are unchanged. See the Viz Mosart Release Notes 5.16 and the Viz Mosart Administrator Guide, chapter Security in Viz Mosart Ecosystem.

Note: Enabling OIDC authentication on a Mosart Server switches off the shared REST API key entirely. The key is not checked at all, so every integration that authenticates with X-API-Key is refused with 401 — including the Elgato Stream Deck plugin and your own scripts. This has been the behavior since OIDC authentication was introduced in Viz Mosart 5.15. Plan for it before enabling authentication in production.

Deprecations

Recent notable changes

• 5.14.0: the Keyable Timing Display is deprecated, and is no longer included in the Viz Mosart Timing Display installer.

• 5.14.0: the installer for ActiveX NRCS plugin is no longer included, since the ActiveX NRCS plugin was deprecated in Viz Mosart 5.13. Customers will need to use the HTML-based plugin (Mosart Web Apps NRCS Plugin).

• 5.12.0: the legacy Showmaker Windows application is no longer supported. The new Showmaker (currently in early access mode) is part of the Mosart Web Applications (Mosart Web Apps Showmaker).

• 5.11.0: the MMTrio executable is no longer included.

• 5.10.0: It is expected that users of Viz Mosart have now migrated to the Combined Manus Administrator introduced in Viz Mosart 5.2.0. From this version of Viz Mosart, the two original iNews and MOS versions of Manus Administrator are deprecated.

Upcoming changes

• In a future version of Viz Mosart (version TBC), support for the Viz Mosart Timing Display client application will be deprecated. Customers are encouraged to migrate to the HTML-based timing display that is available through the Mosart Web Applications. Vizrt is continuing to strengthen the web-based architecture which serves this timing display, and to enhance its functionality where customer experience exposes use cases which are not yet fully satisfied.

• In a future version of Viz Mosart (version TBC), the Keyboard Shortcut Editor (legacy) in the Viz Mosart GUI will be deprecated, to be fully replaced by the new improved Keyboard Shortcut Editor. This new editor is already available in parallel to the original one in the Viz Mosart GUI. Customers are encouraged to start using this new editor, since Vizrt will continue to enhance its functionality, based on customer experience and feedback.

Installation and Upgrade

Installing for Current user only or for Anyone who uses this computer

Normally, Viz Mosart applications are installed for Anyone who uses this computer, but in some situations it is preferable to install for Current user only. If you have a previous installation for Anyone who uses this computer and then install for Current user only, Windows' Apps & Features will show two installations of the application, both the previous one and the new one, and you will also see two shortcuts on your desktop. This is a feature of Windows, but could lead to confusion with subsequent updates.

• A recommendation to avoid this particular situation is to uninstall the previous Viz Mosart application before installing the new one.

[*] The various Viz Mosart applications shall normally always be on the same version, to ensure compatibility of features. If the Viz Mosart applications were installed under the various users' dedicated locations, then during an upgrade, you would have to repeat the installation of a new version for all Viz Mosart users for that computer. In addition to the time and effort this would require, you risk that some users might miss the upgrade. When one of these users later starts a Viz Mosart application, for example the Viz Mosart GUI, it would no longer be compatible with the commonly upgraded Viz Mosart applications, like the Viz Mosart Server.

Please refer to the Viz Mosart Administrator Guide, section Installation.

System Requirements

Recommendations

For further details, see the Installation > Prerequisites section in the Viz Mosart Administrator Guide.

General

• Microsoft .NET Framework 4.8.

• Microsoft Visual C++ 2015-2022 Redistributable (both x86 and x64).

• Microsoft Edge WebView2 Runtime (x64).

Viz Mosart Server

• Microsoft Windows Server 2022.

• Microsoft Windows Server 2019 (only with Extended Support from Microsoft - until 2029-01-09).

• Microsoft Windows Server 2016 (only with Extended Support from Microsoft - until 2027-01-12).

• Microsoft Windows Server 2012 R2 (only with Extended Security updates from Microsoft - until 2026-10-13).

Viz Mosart client computers (GUI, Audio Panel, Timing Display, Audio Player)

• Microsoft Windows 11.

• Microsoft Windows 10 (only with the Windows 10 Extended Security Updates program).

Network Bandwidth

• 1000 Mbps (Gigabit) Ethernet card is required on the Viz Mosart client computer if NDI is used for live preview in the Preview and Program windows.

Upgrade

As a standard procedure, always make backups before upgrading. Please backup all files in the following locations:

• C:\channeltemplates

• %localappdata%\Mosart_Medialab

• %programdata%\Mosart Medialab\ConfigurationFiles

• %programfiles(x86)%\Mosart Medialab\<Mosart application>\ConfigurationFiles

• All files with extension .exe.config in folders %programfiles(x86)%\Mosart Medialab\<Mosart application>\ where <Mosart application> is the relevant Viz Mosart application (for example Mosart Server, Mosart GUI).

Windows registry settings for:

• HKEY_CURRENT_USER\Software\[Wow6432Node\]Mosart Medialab

• HKEY_LOCAL_MACHINE\Software\[Wow6432Node\]Mosart Medialab

For the upgrade procedure, see the Viz Mosart Administrator Guide, section Installation.
You will always find the latest updated documentation for Viz Mosart at the Vizrt Documentation Center.

If you do not have Internet access to the above documentation, a quick guide for installation is given here:

1. Download all relevant Viz Mosart installation files to the preferred location.
   The default location is C:\Mosart\Installers. You are advised to make a sub-directory for the installers for a particular version/build containing all the MSI installer-files and any other supplemental files.

2. Stop all Viz Mosart Windows services.

3. Double-click the installation file, and follow the prompts to complete installation. Note that after completing this step for the Viz Mosart Server and the Viz Mosart GUI, the documentation is available in the installation sub-folder Documentation.

4. Repeat the above step for all relevant installation files.

5. As the last steps you may need to start a set of Windows services to make Viz Mosart run properly (not needed after installing the Viz Mosart Server or the Viz Mosart GUI client, these services are started by the installer). The services are configured to automatically start when the computer is started. The safest is to reboot the computer to verify that this automatic start of the services is working.

Installations with Viz Mosart in several galleries

If you have several galleries running an earlier Viz Mosart version, like Viz Mosart 3.x or Viz Mosart 4.x, you can safely upgrade one of the galleries to Viz Mosart 5.x while the others stay on their current version.

Previous Versions

In accordance with the Vizrt Global Support Handbook section Software Lifecycle, support for older versions of Viz Mosart ends 24 months after a subsequent minor or major version is released.

• With this release of Viz Mosart version 5.17, earlier versions will therefore no longer be supported after 2028-09-07

• At the date of this release, Viz Mosart versions 5.7 and earlier are no longer supported.

Documentation

Latest, continually updated documentation for Viz Mosart 5.17 is available at the Vizrt Documentation Center.

Support

Support is available at the Vizrt Support Portal.