Crash when closing any Soundtoys VST FX plugin

[bkunda]

Issue type

Crash or freeze

Description with steps to reproduce

1. Add a VST FX plugin from Soundtoys
2. Close the plugin

MuseScore Studio crashes

Supporting files, videos and screenshots

logs-14Apr26.zip

Screen.Recording.2026-04-14.at.11.19.00.pm.mov

In which versions of MuseScore Studio is this issue present?

4.7 and master

Regression

Yes, this works in the latest released version and is broken in the nightly builds

Operating system

macOS 26.3

Additional context

Crash does not occur in 4.6.5.

Checklist

• This report follows the guidelines for reporting bugs and issues
• I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible