Audacity exports MP3s and WAVs as a ".FILE" on Windows 7

I’ve had this problem for quiet some time but usually, when it happens, I export it as a .WAV (it still turns into .FILE), then I close and open audacity and drag in the .FILE and convert it into a MP3 or WAV (again) and that usually fixes the problem but now, it doesn’t seem to work anymore. Has anyone experienced this before?

As Audacity should be warning you, don’t type dots (periods) in the file name because this prevents Windows figuring out the correct extension for the files. Please read here for a full explanation:
Audacity Manual .