Can't launch Clip target

I create a new clip target in my project. When I try to run, an error occurred.

'The request was denied by service delegate (SBMainWorkspace) for reason: Unspecified ("null").'

I have no idea about that. macOS Catalina 10.15.4,Xcode Version 12.0 beta 3
Answered by zlata_c in 625570022
Try to change your build system to New Build System. Go to File->Workspace Settings for this.
Accepted Answer
Try to change your build system to New Build System. Go to File->Workspace Settings for this.
Can't launch Clip target
 
 
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