Hi ,
FWIW , here is the procmon64 trace of reaper_host64.exe and bbw* processes from beginning of song generation to the crash :
procmon64_logfile using the build 4.5.33 of the VST2 plugin in Reaper 6.57 , driver asio RME Babyface Pro @ 44.1 Khz / 24 bits
No trace of a Band In A Box program , only the backend
but it seems that the size of bbw64.exe and bbw4_64.exe are similar ( 54946 kb vs 54981 kb) ?
There are several WerFault.exe process near the end
Also , I have tried to do a test with "dummy" audio driver in Reaper with the same issue.