95% of the time this is caused by one of your owners putting a cute (but unreadable) character into their FRANCHISE INFORMATION PAGE of your MyFantasyLeague League.
- Go to your MyFantasyLeague.com league page
- Go to "REPORTS > FRANCHISE > FRANCHISE INFORMATION"
- Scroll down and for odd characters in team names or stadiums,etc. These characters tend to be things like: �, ™, ®, etc
- Edit your owners information, and remove those characters completely.
- Once you do this, attempt to re-Export your draft data from FanDraft to MyFantasyLeague,and it should work.