I discovered that all information about links to my site disappeared from Google Webmaster Tools.
Last time I checked the "Links to your site" page in GWT there was nice list of linking domains and all. But now there is only "No data available."
There were no changes to the site contents.
Why could it be? And what can I do to fix this?
About a month earlier I found that PR of all my pages dropped by 2 points. May these changes be related?