As of midday today, my AdSense account suddenly just stopped working (now it's only showing blank ads).

I didn't receive any messages or notifications about violating AdSense policies. I have my domain opted as a valid domain in the account settings. What else can it be????

I would tend to beleive that if you violated their policies, they would have notified you via email as well. Must be something else.

If you take a blank web page, locally on a computer and insert the adsense script for your account, does the ad show?

It does ... I was able to figure out that my domain got banned, and not my account. Working on resolving this :( UGH.

Super busy at the moment but I'll come back in a little bit and post the details. I know what happened.