UE 5.1

UI play button doesn’t work and give errors, I´m guessing I don´thave the right name for the level? My level is called MMmap but then I put that in nothing happens.
Can someone help?

Same problem.
with 5.0.3 package and 5.1 editor window everything works normally but with 5.1 package the button no longer work.

(I think there is another problem. UE 5.1 packaging only start map)