Can't Upload to Vimeo

OS X Yosemite 10. 10. 5

iMovie 10. 0. 9

Model Name: MacBook Pro

Model Identifier: MacBookPro5,3

Processor Name: Intel Core 2 Duo

Processor Speed: 2.66 GHz

Number of Processors: 1

Total Number of Cores: 2

L2 Cache: 3 MB

Memory: 8 GB

Bus Speed: 1.07 GHz

Boot ROM Version: MBP53.00AC.B03

SMC Version (system): 1.48f2

I now can't upload to Vimeo from iMovie. I've done this dozens of times. My Vimeo account is working, the user/password has been checked and verified, added correctly to iMovie/Vimeo login dialog, but it keeps saying the user/pass combination could not be verified.

I've gone into keychain and delete the key for that account and attempted to login again through iMovie and it persists with the same.

I've restarted my computer, that didn't fix it.

I've tried logging into another Vimeo account that I have and it gives the same error, so something is wrong with iMovie's social media upload login user/pass dialog window, and not the account user/pass I'm entering.

How do I fix this?