Over the past 36 hours, I've been seeing sporadic reports from webmasters that their link data within Google Webmaster Tools is either now being under reported or coming up as "unavailable."
Here are two webmasters posting about the issue, one on Google Webmaster Help and one on Twitter but there are plenty more. Personally, I cannot replicate it on the several sites I've checked, so it might be a sporadic issue impacting only a small group of sites?
One webmaster said:
The link data in Webmaster Tools is shown as unavailable in Webmaster Tools. It was working fine a few weeks ago.
Another said:
My links are gone
Clearly this can be concerning for SEOs and Webmasters, but I suspect it is just a reporting glitch and you do not have to worry. This happens fairly often, believe it or not.
Forum discussion at Google Webmaster Help and Twitter.