Mac clean removes engine files

If you hit ‘Product->clean’ in xcode it will remove some engine files required to compile.

Using the verify function on the engine from the launcher replaces the files.

Possibly the cleanup scripts should be tweaked to ignore the engine files.

Hey -

A bug report for this issue has been entered (UE-23624) for investigation. For now if you do need to use the Clean command then it is best to follow with running Verify from the launcher.