Multiplayer Accessed None Property Error

I try to program a Multiplayer game but my MainWidget keeps sending me the eccessed none error every time i test to run it on a dedicated server with 2 players:
Error Blueprint Runtime Error: Accessed None trying to read property MainWidget from function: ‘ExecuteUbergraph_CharacterBP’ from node: Add to Viewport in graph: EventGraph in object: CharacterBP with description: Accessed None trying to read property MainWidget

Sounds like you didn’t create the widget before trying to add to viewport.

Post a screenshot of your Blueprint.

UMG objects are not replicated, in-case you were trying to replicate the widget and add it to several screens.

sounds to me like you may need and isvailid? check, a screen shot of the area in the bluperint its throwing the error might get you more specific help