Yes, I also use iZotope plugins.

Yes, I did have some sort of iZotope plugins too. But they we're not in use in my sequences if I recall.

No izotop for us but we do have

BCC

ssphiire

and 

mocha

This just happened again.  None of the tricks worked.. Had to throw the work away and start from scratch.

It's like working with a ticking time bomb.

saw another fix to try 

console

RepairSequence.

and they *** thing opened.  at least this time.

Holy cow, this worked for me!

I'll report back if it ends up not working in the future, but it just saved my morning! Thank you!

Didn't work for me. I have the same setup and same issue

Repair Sequence just stopped woking for us however...

If your seqeunce contains subcaps...

Find another system if available and open your bin. Duplicated the sequence. Open the duplicate. Deleted the "Subcaps” in the duplicated sequence and save it. Go back to the bay that crashed and opened the bin. Open the dupicate.  If it does not crash your orginal sequence should open fine now....

?????

makes no sense to me but working multiple times.   

To be fair we also did the Hokey Pkey and turned ourselves around ;-).

Good luck.

This happened to us for larger feature-length sequence from older version of Avid being opened into Avid 2021. Sequence has subcaps, LUT. Could be any number of things. Crashes Avid 2021 every time, until we drag sequence to Source Monitor, create a new sequence and Insert or Overwrite all contents of problematic sequence into new sequence. Avid 2021 then plays the contents without a problem.

Is it possible to get a copy of a sequence that reliably crashes when opened on a new Avid? It would be good to pass to Avid to investigate.

Not sure about original poster but avid has copies from me under Case 04180488.   

I also encounter 10 to 20 minutes start up time making trouble shoot a process that crashes your systme 9 times out of 10 and very frustration process....

Same problem.

Fix is to 'remove color adapters' under the refresh sequence command.

But then again, this morning it didn't work.

MC2021.6, Catalina, BM Decklink card 

Is ayone at Avid actually doing something about this? There doesn't seem to be much of a response and it's clearly a fundamental issue since the new avid interface has been implemented. I'm working on a large show with 6-8 editors and every person on the new interface versions will have this problem 3-4 times a week. I literally can't load a sequence with any effects on it unless I load, say a rushes sequence (something without any effects) in to the source + record monitors several times. It then seems to kick start Avid into thinking it can actually work somehow. This isn't a plausible way of working though! 

.This bug is suppose to be fix in 2021.9.

I have about 15 of my systems testing it at this point and it feels like this and many other bugs are corrected.  

I'm going to upgrade now.. Finger crossed.