Thanks for getting in touch. I'm so sorry for the trouble you've encountered.
Behance recently changed its signup process to integrate more fully with Adobe IDs. Ironically, this caused a bug in the Behance-Lightroom integration that we are currently working to fix. If you signed up for a Behance account after April 10, 2014, you will not currently be able to share to Behance from Lightroom.
However, you can still share from the apps Photoshop, InDesign, and Illustrator.
Please upload directly to Behance by logging in at Behance.net
Note that the other Creative Cloud integrations (Photoshop, InDesign, and Illustrator) will continue to work as normal.
Thank you so much for your patience, we'll be in touch with an update soon.