The engine should make assets compatible when upgrading…
But it is also possible that the engine has done it wrong. (It wouldn’t be the first bug the engine has).
I don’t know if this will work… but if the problem is really that the file is created you can try this.
-Delete the file
-Change the permissions of the (DerivedDataCache\VT) directory to read-only
That should prevent files from being written to that directory.
If it works, maybe that will give you more time to find the real problem.
If you succeed, click on all the “StaticMeshActor” (one by one)
If you find an invisible one, delete it.
I’ve encountered one like this a few times… I probably deleted the asset but the reference didn’t get removed from the level.
I remember a post from someone who had a similar problem with city buildings
Best Regards!!