I'm assuming something broke in a module somewhere because none of the wiki's notices like script status and the Personal template show their text. The below is on my chromebook, but this is also like this for my phone.
I think it's indeed the module and has been fixed since.
By the way, to temporarily disable custom CSS and JS you don't need to delete the code from the files, there are URL parameters for that, which you can add at the end of the URL:
?useusercss=0
?useuserjs=0
?usesitecss=0
?usesitejs=0
?safemode=1 (for all of the above together)
(Use & instead of ? if the URL already contains a ? )