This was like the 5th crash in this one project. Each time was after an hour or so of editing and happens right after I stop/play, it happen in REAPER v5.965, v5.97, v5.971 and v5.972.
In VS I see in the one list is like 4x reaper.wave.dll, then 4x jsfx. I swapped out most the JSFX for others but that didn't help.