Could this be why my adsense has tanked?

I've been having issues with adsense since Fri. Suddenly I went from making about $100.00 a day to zero. My traffic decresed to about 1/4 of what it was and my cpc went from 2-3 dollars on average to zero. I notice adsense will record clicks for what my normal amount was and when I check later, it has gone back to zero. I know adsense does this with invalid clicks but as far as I can tell, these are the same types of clicks I was getting, nothing seems to have changed. Now, in my account settings, I find this:

"Our crawler was unable to access your page to determine its content and display relevant ads. When our crawler can’t access the content, often we won’t show ads resulting in lower revenue and coverage. Other times, we’ll show ads that are irrelevant resulting in lower CTR. Follow the links in the ‘How to fix.’ column to correct these errors and improve AdSense performance."

Could this be the problem? And, if so, what can I do about it? When I go to the page they say is not there, it comes up fine for me and ads are showing.

Thanks.