I installed the second Beta of 10.11 and Xcode 6.3.2 has stopped running.
The error is:
In order to open "Xcode", you need to update to the latest version.
The version of Xcode installed on this Mac is not compatible with OS X El Capitan. You have "Xcode" 6.3.2. Download version 6.3.2 for free from the Mac App Store.