After app launches I see message:
Loading a plug-in failed. The plug-in or one of its prerequisite plug-ins may be missing or damaged and may need to be reinstalled.
Sierra 10.12.5 (16F73), Xcode 9 9M136h
I would delete that install and the download used for it, then re-download and install from that resource. Be sure to have several tens GB free space, at a minimum for that process.
I have also encountered the same problem. I have re-download & unzip the XIP, and that's OK.
I solved it by deleting this folder "/Library/Developer/PrivateFrameworks" and relaunch xCode again.
Same story with Xcode 16 Beta 3. Tried unzipping it with Keka but it fails and Keka says the data is corrupted. If you use the native archive utility to unzip it, you can get the app but it fails to start. Gives the error stated above about a failed plug-in.
