Just a little PSA here
Openbeta, DCS Ver 2.7.[whole lotta numbers here] - Nov 2021 and up to date.
Short Version: Suddenly it appeared to be freezing when running from ME; sitting there staring at a blank window. Finally looked at the dcs.log file and the last line was something like:
WORLD…\Temp\DCS.openbeta\tempMission.miz
It seemed to be frozen there or taking a really long time to load this file. So I went to the folder:
“C:\Users<your id>\AppData\Local\Temp\DCS.openbeta” and deleted everything inside (it’s a layout similar to a miz file, but expanded/un-zipped.
Long Version
This mission has about 300 “.ogg” files (all very small and together only about 200k). Well, instead of ~300 “ogg” files there was 33,000!!!. Plus. Something went all pear-shaped there. After deleting everything as mentioned above all is well in DCS World again 
Hope this helps someone in the future.