Can't comment selection

Question

Sometimes, it seems I can\'t comment my code with the usual shortcut (command + /) under Xcode 8 Beta 4. The option is disabled in the menu (screen

Answer 1

This still (May 2017) happens to me occasionally in Xcode 8.3.2. Quitting Xcode is not enough to clear it up. Logging out and logging back in fixed it for me. I did not have to run a command line tool or reboot.