I dug into it today by simplifying. I changed the file naming script to a simple preset, disabled all my autorun scripts, and focused on the album title. Changed $eq(%media%,12" Vinyl) to $find(%media%,Vinyl). I tried creating a new hidden variable if one of the above was true. Nothing worked.
Lastly, I just tried to get it to simply rename the album unconditionally:
$set(album,%album% \(LP Rip\))
When I ran it like that, the app crashed without notice. (Win10 x64)
I restarted it, reloaded the same album, and the simple script ran just fine. I tried the conditional script, and it worked fine as well. I went back to my file naming system, and added all my scripts back one by one refreshing the album each time. There were no issues.
I’m now back to my more complex original album naming script:
$if($or($ne(%date%,%yearreleased%),%_releasecomment%,$find(%media%,Vinyl)),$set(album,%album% \($if($ne(%date%,%yearreleased%),%yearreleased% Re,)$if(%_releasecomment%,%_releasecomment%)$if($find(%media%,Vinyl),$if($ne(%releasecountry%,US),%releasecountry%)LP Rip)\)))
…and everything is still good. I’m using $find now instead of $eq, bujt that’s the only difference.
So the issue was transient. If it happens again, I’ll try to spot the trigger. At least now I know to just restart the app.
Thanks for all the replies!