Yes. I drag MKV1 onto the timeline. No problem. MKV2. No problem. MKV3 - hangs up while dragging. Stops responding. Crashes.
You will never bring that MKV file into any other instance of VP21 in any way. Fresh veg file. Veg file already with MKVs on the timeline. Even putting in a remuxed mp4 and trying to replace it causes Vegas to freeze up.
The freeze is one of those "Uncle Bill" freezes - you get the reporting to Microsoft message and no Magix prompt. So, I'm wondering if it's some kind of tick in the registry? It's the only explanation (short of my file not opening on anybody else's system, either - which would be its own weirdness...)
I just like using the MKVs because they aren't VFR like the remuxed MP4s that OBS generates.