[43.00] (Random?) Adding an event to a widget fails, errors out and breaks that UMG forever

Summary

I got to a weird state where I could not add any new event into a UMG
I could add standard vars (bool) with no error, but whenever I added an event, UMG would fail compile and I would get those:

LogBlueprint: Compiling Blueprint ‘/fb1e1665-ac09-42a6-bd3b-2bf1b2d50b0f/TestUI/Test.Test’
LogBlueprint: Error: [AssetLog] /fb1e1665-ac09-42a6-bd3b-2bf1b2d50b0f/TestUI/Test.Test: [Compiler] This blueprint (self) is not a VerseUIUserWidget, therefore ’ Target ’ must have a connection.
LogBlueprint: Error: [AssetLog] /fb1e1665-ac09-42a6-bd3b-2bf1b2d50b0f/TestUI/Test.Test: [Compiler] Found more than one function with the same name soemevent; second occurance at soemevent

I would also get those errors in the log when adding the event:
LogTemp: Error: Missing BackPointer variable on Test, can’t generate event function for VerseFieldInternalVariable_soemevent.
LogBlueprint: Warning: [AssetLog] /fb1e1665-ac09-42a6-bd3b-2bf1b2d50b0f/TestUI/Test.Test: [Compiler] Failed to generate the Verse event function for VerseFieldInternalVariable_soemevent.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Verse

Steps to Reproduce

Make a new UMG Widget, pick user Widget as class
Add a new event, see errors

Expected Result

Adding an event just works without errors

Observed Result

see errors in summary
After that happens, that widget fails compile forever with same errors, even if i delete all events/vars
Only way I found to recover it was to do a Assets Action → Reload

Platform(s)

Win 64