- Go to http://en.wikipedia.beta.wmflabs.org/wiki/Special:Preferences#mw-prefsection-betafeatures and make sure that Compact personal bar is disabled
- Go to http://en.wikipedia.beta.wmflabs.org/w/index.php?title=References&veaction=edit&debug=true
- See in Firefox 36's error console:
TypeError: mw.beta is undefined http://bits.beta.wmflabs.org/static-master/extensions/VectorBeta/resources/compactPersonalBar/defaultTracking.js :5