A WebmasterWorld thread reports that Yahoo Search Marketing is down for some. When some advertisers are trying to use Yahoo's pay per click ad system, they get an error.
The error reads:
We are currently experiencing a technical issue that is causing the ads of some advertisers to not be displayed properly to users. This may cause your account to receive a lower volume of clicks than normal. We are aware of this issue, and are working diligently to resolve it as soon as possible. We apologize for any inconvenience this may cause you.
So far, we have two confirmed reports of this bug in the WebmasterWorld thread.
I am not sure how widespread the issue is or if it is resolved yet.
Forum discussion at WebmasterWorld.
Yahoo updated the thread, saying:
I can confirm that this issue was resolved at approximately 10:30 a.m. Pacific Time on December 15, and ads should be displaying normally since then. Sorry for any inconvenience this may have caused.