I have a player with UMG widget which he creates on BeginPlay. It works fine when hitting play with only 1 player, but if you set the number of player > 1 it will crash somewhere related with the setting the owner of the UMG widget.
EDIT: repro project
Thank you for taking the time to report this issue. With the project you provided I was able to reproduce the crash you are experiencing. I have made a bug report for the issue with the number UE-10876.
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Hey again nafonso,
I was told a work around for the crash you are experiencing is to add a delay after the Event Begin Play and create your UI at least a frame after.
I hope this works for you!
Thanks, one of my friends works there and he told me about that workaround. ;-]