I know this is old. But this is for anyone who searches and finds this when encountering the same problem. For me, I am using Xcode 14.2 and inline errors stopped appearing when working in a playground. I would get errors when I attempted to run test code, but nothing inline. So I suggest you check the folllowing: Menu>Xcode>settings General tab. Issues should be set to "Show inline". Ok, this was set correctly in my case and it was still an issue. So continue to 4. Accounts tab. Here I had an error indicating I had logged out of my AppleID account. Log back into your appleid account. Bazinga, inline errors started reappearing. Good luck. Stay safe. Be kind.