xcodexcode6.3ios8.3ios8.4xcode6.4

Xcode 6.3 not running iOS 8.4 - update to 6.4 fails

I have upgraded my iOS to 8.4, then I tried to run Xcode 6.3, it asks it can't mount the device since it's running 8.4 version (".. running a version of iOS that is not supported by this version of Xcode.") When I try to upgrade Xcode to 6.4 - update fails every time with error message (try again using purchases).

Any suggestions how to solve this?

Solution