So I just installed todays new beta build of iPadOS beta 10 and when I enable stage manager safari won‘t load up and my iPad goes back to the Lock Screen.
first time it happened a crash message appeared as well.
I am having the same issue, but not only with Safari but with Files app. Both crash when launched with Stage Manager. Running the beta on an iPad Pro 2018 (in case this is important).
Actually managed to solve the issue. I have opened both Safari and Files in Split View and, once both opened, I have activated Stage Manager. Everything works fine now.