I cannot add mp3 files to iTunes 12.1.1.4 anymore

Hi everybody,

I'am on Windows 7 and all of a sudden, I cannot add mp3 files (nor other types) to iTunes 12.1.1.4 anymore. The administrator function isn't checked in the compatibility pannel of iTunes properties. I tried to uninstall and reinstall iTunes. But nothing change.

Thanks,

Freddy_Willy