If your still having issues, please follow my instructions below...
1. Log out of battlelog website and origin. (Must do both steps)
2. Find EACoreServer.exe typically located here C:\Program Files (x86)\Origin Games\Battlefield 3\Core\EACoreServer.exe
3. Delete File
4. Log back into origin(must do a full logout previously, so you must enter username and password again)
5. Check for Origin update and then do a repair install
6. Go to Battlog Website and Relogin with username and password
7. Join a server and it might will say your session has expired. Click on Reconnect(might take few attempts) and issue will be solved.
if your still running into issues, download the pb setup and check for updates and then run my procedure again and u will have no more issues.
http://www.evenbalance.com/?page=pbsetup.php
Your Welcome 🙂