Title says it all. XCode does not autocomplete extensions, both default and ones I added. For instance, when I type
UIButton().tit
XCode does not show me a list of extensions that contains those three letters. On my laptop it worked fine, but on my desktop (iMac 2014 with 5K display) it does not work.
Deleting the Derived Data folder, restarting XCode after toggling the autocomplete option in preferences, and toggling the target membership did not help.
Any suggestions?