Problem exporting to MP3

This problem is similar to uploading a score on the .com site, with the exporting moving at a snail's pace, ultimately quitting at 49% with a result of no audio. In this case I get a blank MP3 file. (When uploading a score at the site, the result is a published score with no audio.) In this case I want just an MP3 of the score.

This is a 20 stave piece I had on Ver 2.3.2 It is 52 kb. There is no artwork and the sounds are from one font set. (Windows 10/64)

I have read this similar threads about this topic:

I do "save to score" (synthesizer setting)

I do have the MS gen font in my synth, but this score only uses the SymphonicSounds font. I have had success with MP3 before up to 15 stave scores. The two font sets in my synth are thus ordered:

Symphonic Sounds
MS Gen

There have been times (with the uploading to the site) where a future attempt would proceed successfully. No one (at the site) seems to know why.