Hello Woj and Tonnie,

I'm experiencing the same issue and am a bit relieved to see this issue may not be install-specific after all. I contacted support yesterday with details about the same closing/crashing issue and also suspected that the issue was confined to a single song/style( _SLACKS). Backup copies of the same file restored to the working directory from an external drive misbehave in the same way (i.e.close/crash the app upon opening the song).

The problematic style in my case does not contain RT 4656. All tracks in the latest song file have been frozen and unchanged since July 2023 and replayed without issue in v2023 dozens of times over the subsequent months. Multiple frozen arrangement file versions of the same song with the same style exhibit the same problem, however, the initial =unfrozen= arrangement version with the _SLACKS style will still play without issue. If I take that unfrozen version and save it to a new filename, I can freeze the tracks, save and reopen/play the file as expected; but (wait for it), if I unfreeze the tracks and change the key to the desired key of the July version and attempt to regenerate the song, the app crashes without producing any error logs I can discover. Reopening the app, I can replay the saved frozen version of the song, unfreeze and regenerate/play it in the same key, but as soon as I change the key and regenerate the song, the app crashes.

I don't know if that info lights any bulbs or provides any clues, but I wanted to chime in that the issue may not be limited to a few users/styles.

Kind regards,
Inki