Also experiencing this issue.

By creating a new project and painstakingly moving the files/settings over one by one from my old one too see where it fails I found out that when I have more than 5 Configurations it starts to fail. It's rather random but it might give apple devs some clue on how to fix it. My project is using cocoapods. When I removed the configurations, XCode continued to fail so it's not easy to reproduce. I also created a fresh project with the podfile from my big project but that one didn't fail on more than 5 configurations. Only thing I know is that this is a pretty serious error and makes programming with XCode a complete nightmare.

Is there seriously nothing being done to address this issue? Using Rosetta doesn't help, and neither does unchecking show live issues. The IDE is on the border of being unusable. This needs to be fixed ASAP!