Question: XCode 6 Beta 5 and autocomplete stopped working. I thought problem in Beta 5 but I've reinstall to Beta 4 and it's still not work but it did before. I check preferences for "suggests" and I tried to delete Derived Data but it doesn't help

Answer: 
I found the solution. Problem was in an array.
I have big array like: 
`let array:[NSString] = ["first","second"...]`
 I changed it to 
`var array = ["first","second"...]`
I don't why it's happened but it works. It was so hard to find the problem.
Tried to clean/delete derived data multiple times. Autocomplete was disabled in some files, but not App Delegate. After a while I saw red libraries int he project navigator. Those are managed by cocoapods. The solution turned out to be:

* Navigate to the project root folder
* Delete "Pods" directory
* open terminal, type cd
* drag the project folder there to get full path
* run pod install

Upon reinstalling pods, syntax highlighting and code completion is restored in the affected files.