UUserWidget Crashes Multiplayer Clients.

Answerhub Report: [Repro] Adding UUserWidget To Viewport on BeginPlay Causes Crash On Clients - UE4 AnswerHub

Effectively it’s not possible to add a Widget to a players viewport on BeginPlay() (which seems like the place to do it right?) - especially in Multiplayer. I got around this previously by using a Delay, but this isn’t a very nice workaround and has the potential to make debugging pretty difficult.

I think this is partially related to another issue whereby Widgets are not assigned to a ‘World’ of any kind. When you switch to a new level for example, Widgets that aren’t destroyed remain on screen forever.

Hello i belive you are having issue UE-11311 i can not find the thread atm.
But Epic did confirm it was a fix for it come 4.8.

There are some more info on it here, and GitHub link to the fix.

Ah okay, I’m still seeing this in 4.8 Preview 4. I’ll check the link!