Need help finding source of NotImplementedException after 2019 upgrade

I’m seeing the following error printed twice in my console after upgrading from 2017.4.22f1 to 2019.2.0f1:

NotImplementedException: The method or operation is not implemented.
System.Environment.FailFast (System.String message) (at :0)
.ok-lj.nkm+nl–lm.
nl-,njnj
,no-. (System.String ) (at :0)
.l+nml.o-,joll
n++
n
-j+n-k-
n.,. (System.Object ) (at :0)
System.Threading.ThreadHelper.ThreadStart_Context (System.Object state) (at :0)
System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) (at :0)
System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) (at :0)
System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state) (at :0)
System.Threading.ThreadHelper.ThreadStart (System.Object obj) (at :0)
UnityEngine.UnhandledExceptionHandler:m__0(Object, UnhandledExceptionEventArgs)

It appears to be the same issue as found here (except I don’t have sufficient permission to reply to that thread apparently), but I’ve been removing DLLs and restarting Unity all weekend to see if it helps and nothing has made a difference.

There has to be a way to get at the underlying info to see where the problem actually is. Any advice on finding a solution would be much appreciated.

Bump.

I’ve followed the advice at the link mentioned above and removed all DLLs from our project (600+), then reintegrated them one by one by restoring each DLL and restarting Unity. But the exceptions only show once they’re all included again and the corresponding errors are resolved, not specifically because of the last DLL re-added. Restoring them in a different order results in the same thing.

Trial and error isn’t a feasible way of going about fixing this, and I’ve spent two days fighting with it now.

How can we solve this issue?

FWIW, I’m running into the same issue upgrading to 2018.3.14f1 as well.

Really stuck on how to get past this one. Anyone from Unity care to chime in?

I’m still stuck at this error. I’ve successfully upgraded everything to 2018.2.21f1, but I’m completely stuck on 2018.3 due to the above error.

Any advice on solving this would be super helpful.

Same problem on unity 2018.4.15 any way to fix that?