error in Playgrounds app

I'm creating a Swift Playground in Xcode and when I run it there, there are no problems. When I try to run it in Playgrounds App on my iPad, there is always an error "there was a problem encountered while running this playground. check your code for mistakes". When I turn enable Results off, there is no error and everything works fine. Does somebody know why this happens? If I just ask the judges to turn "enable Results" off, will my playground be reviewed even if there is an error with turned on "enableResults"?

The swift playgrounds apps can't run your code as fast when results are enabled, so by turning it off you allow it not to breakpoint somewhere where it might if the previous code wasn't running correctly because it's slower.

error in Playgrounds app
 
 
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