I didn't see this reported yet, hope it is not a repeat, it only happens in x32 version, version 4.12, go to options, scan for new DX plugins, and CRASH! Like I stated I can only reproduce it in 32bit version, 64bit version works fine.
OK installed version 4.13, went to options, scan for new DX plugins and REAPER crashes, this is in x32 version, I do the same exact actions in x64 version and it behaves as expected, no problems. W7 x64 list of DX plugins to follow.