Export makes a 15 file instead of wav or mp3

I have used Audacity for years and have loved it until now. I recorded live rehearsals on my laptop. previously when I exported it worked fine… now when I export it doesn’t make a .wav or .mp3 file it makes a 15] File (.15]) What kind of file is this and what is the problem

When you Export, it asks you what type of file or Format you want (attached at bottom. Click on the graphic). What does yours say?

Which Audacity (all three numbers) and which Windows?

When was the last time you restarted your computer. I mean shut it down to zero, go make coffee and then restart it.

Screen Shot 2015-06-27 at 9.51.59.png

It exports a “.15” file because you typed “.15” at the end of the file name and ignored Audacity’s warning about doing that. To solve the problem if you need dots in the file name, add another dot and the extension you want such as WAV or MP3 at the end. To export a file called “Song.15.wav”, actually type “Song.15.wav” (without the quotes).

See here for full explanation: Audacity Manual.