UIKit.h not found error

Question

I made a single view app for the ipad, with a movie, webview and button, and I get this error when I try and run it. I have restarted the application, and reinstalled it, but nothing is working. This error keeps coming up in my MoviePlayer_Prefix.pch file. Can someone help me out?

Answer 1

I have had the same issue with being unable to compile project due to UIKit.h not being found + "unable to load standard library for target..."

The solution for me was very simple - to quit (CMD+Q) and relaunch Xcode. I have found out that with Xcode opened, macOS seems to have removed command line tools for Xcode because it was preparing for a update and relaunching Xcode triggered the "install additional components" update and it made the problem disappear.

Answer 2

Like Faul Textor said, most likely your XCode updated to 12.1 but your Command Line Tools didn't. You need to quit XCode completely and then start it again and you should get a pop-up saying "Install Additional Components" Sorry, this should have been a comment to his reply but I cannot do that.