Just wanted to add, that I’m getting the exact same error when I try to reopen the project.
It does compile, but launching the packaged build also results in an error: "Assertion failed: IsValid() [File:Runtime\Core\Public\Templates/SharedPointer.h] [Line: 890]
Updating EOS in the Epic Games Launcher Settings didn’t help and I also tried with a fresh install both for the launcher and engine on another system (both windows 10) and got the same issue.