Several at nowiki has reported blank web page lately, but resetting beta functions and then turning ContentTranslation back on solved the problem. Not sure what is going on, but it sounds like something isn't updated correctly.
From the text in the reports it seems like they are using Special:Preferences/reset so it is a pretty hard reset to get the web page going again.
First report was several weeks before the last system upgrade.
It could be that the root cause is somewhere else.