I just ran into this, and after breaking into the debugger, I noticed the ctor was stuck on a generated wait on a condition variable. I realized this was due to the thread-safe static initialization, and was able to work around the issue by removing the “static” qualifier from the offending FClassFinder. This sounds like an engine bug to me, or at least a huge insidious hazard that should be specially detected and alerted.
I’ve had this recur a few times with 4.21 as well. There’s definitely a long term bug here.
There’s a comment below from ‘Neverender’ that might be a hint at the issue:
I just ran into this, and after
breaking into the debugger, I noticed
the ctor was stuck on a generated wait
on a condition variable. I realized
this was due to the thread-safe static
initialization, and was able to work
around the issue by removing the
“static” qualifier from the offending
FClassFinder. This sounds like an
engine bug to me, or at least a huge
insidious hazard that should be
specially detected and alerted.
Sounds like there’s something going on under the hood that needs to be looked at.
FYI, if I uninstall and then reinstall the engine it fixes the problem 100% of the time so far, but it’s not a quick solution to download the whole thing again!