This has started occurring after installing Visual Studio 2015 Update 1. Invoking the CodeRush Find All References shows the references window, and immediately a message box saying:
The type initializer for 'DevExpress.CodeAnalysis.LanguageFeatures' threw an exception.
Pressing "Ok" leaves the references window with a progress bar saying "Searching" and no references are displayed.
We have determined the cause of this issue. It is fixed in the 1.0.7 build, which will be released in the near future.