I have a little issue with the Firefox Compatibility Mode strings in Pale Moon since 25.1. On Windows 7 64 bits at least. Basically, they are still in English while the rest of strings are in Spanish:

As I said, this happens, at least, when using Pale Moon 25.1 or 25.2 64 bits on Windows 7 64 bits. Now, the weird thing is that I have just installed PM4XP in a Windows XP 32 bits OS —overwriting an old Pale Moon 24.7 installation— using the very same language file, and in this case is perfectly in Spanish.

Best.