We have received the report from users who saw MovieRecorder crashing when using the remote control feature with Catalina.
We have identified the issue, which happens in the Thumbnail generation. It happens in a code that hasn't changed since a while, and does not happen with previous versions of the OS, so it's an issue specific to macOS Catalina.
We are working on a new version of MovieRecorder (version 4.4), a pre-release version is available and we advise all users with macOS Catalina and using the remote control feature of MovieRecorder to test that version.
We'll continue working on this and will keep this article updated with our progress.