blank form to login to sims 3 exchange

Try clearing your browser cache or use a different browser.

I launched the exchange window in IE (which I don't normally use and I haven't updated for at least a couple of years) and I was already logged in, so I logged out and when I went to log back in the login pop up was fine. But I normally use firefox (most uptodate version), that was the browser I created my account with and has worked many times in the past. I emptied the cache, as you suggested, but with firefox I'm still unable to login.

Contact a Customer Support game advisor so they can take a look at your account to find out what's going on

Game advisors can be found through live chat.

1. https://help.ea.com/en/contact-us/ 
2. Set your language to US at the bottom
3. Click on Contact a game advisor 
4. Describe your issue with a few words
5. Click on Find a Solution
6. Select Product: ex: The Sims 3 or Origin
7. Select Issue Type: ex: Billing/Purchasing or Account Management
8. Select Platform: PC
9. Click Find solution
10. Scroll down and click I still need help
11. Click Chat Now to chat with a Game Advisor
    

With Pics here: http://sims3.crinrict.com/en/2012/10/how-to-contact-ea.html