Xcode 6 GM crashes when selecting the main storyboard or a xib

Question

I just downloaded the Xcode 6 GM and every time I select the main storyboard (and a specific xib) Xcode crashes.

The error to be sent to Apple contains the following

Answer 1

I just experienced the same thing. It turned out to be a duplicate UILabel in the storyboard due to a git merge. Apparently Xcode will crash if two UI elements have the same internal ID.

Somewhat similar to andrew-burke's method, my method for finding the responsible issue involved tracing through git for the problem change. Steps:

• Iteratively step backward through the git history, checking out each commit until you find the first storyboard that doesn't crash Xcode.
• Once you have the commit that started crashing, check out HEAD and iteratively revert the storyboard changes in the problem commit. Continue to narrow it down until you have the one UI element or one line that will cause a crash.
• Revert the responsible change permanently and restart Xcode. Open the storyboard again and you may be warned about an internal inconsistency. Agree to the proposed changes Xcode makes, but review them.
• If necessary, you may now attempt to re-create the UI element or changes from scratch that were causing the problem before.