Just an update to something that happened to me recently.
I had a procedure which I left without renaming. Once I restarted my project I got a “gnu.expr.Closure” error.
What had happened is that my procedure which I left without naming (default “procedure”) had renamed my linked call procedure’s to an existing named procedure randomly in my project.
If you’re getting random errors on start up, make sure to check your procedure call blocks and confirm they are still linked to the appropriate procedure blocks. This seems to only happen to procedure blocks not renamed by the user.
Let me know if anyone else has come across this issue.