I am unable to save MP3 files

I recently purchased the USB Phono Plus Audiophile Computer Interface from ART (Applied Research and Technology).

The unit came with an installation CD v1.50 which loaded Audacity 2.0.5 on to my lap top which is running Windows 7 Professional with the 64 bit system. I can record to Audacity but I am unable to export in a MP3 format.
I have lame 3.100.1-x64 , lame_v3.100 , and lame3995o-20190620 downloaded.

Every time I attempt to save a recording I get this error message. ! Could not open MP3 encoding libray!
Any help would be appreciated.

The current version here has LAME built-in. (You can download it without signing-up with Muse Hub.)

The easiest thing is probably to export as WAV, then install the new version of Audacity and open the WAV file, then export as MP3.

What he said.

The reeeeeeally early versions of Audacity didn’t have built-in MP3.

Koz

But you will still get the window after downloading that implies you have to sign up. Steve’s link is a better, less confusing prospect: easier download link