[Gimp-user] GIMP suddenly gimpy!

[silverojo]

I looked at your image...while I'm not sure how to solve the problem, I think
I know what it is.

It looks as if GIMP is trying to operate in a foreign language that's not
installed on your computer.  When I use Firefox (in Linux) to view Japanese or
Korean websites, I see those same squares with numbers--they're replacing the
foreign characters.  But if I use Opera (in Windows) with those same sites,
they render properly, because I have those foreign languages enabled in
Windows.

I would do as others have already suggested, and make sure that the GIMP is
completely uninstalled.  Re-install it, and make sure that it's the
English-language version.