After patching our vCenter Server recently we were no longer able to use the "Search Inventory" box to search our virtual infrastructure. When we tried we would receive the following error:
Login to the query service failed. Unable to connect ...
The full error text has been abbreviated.
It appears that a Microsoft Security patch has cause the issue. After removing all of the February Microsoft Windows Updates we could again search the inventory. After installing the patches one at a time we found the the offending patch appears to be MSKB 2645640, which is part of Microsoft Security Bulletin MS12-009.
This patch resolves a vulnerability in the Ancillary Function driver (afd.sys) according to the full MSKB article available at http://support.microsoft.com/kb/2645640
Once we removed that update the Search Inventory function once again worked in vCenter. We will be opening a ticket shortly with VMware to let them know that this patch breaks vCenter. Hopefully they will contact Microsoft so that they can get the search functionality working with the patch installed.
Hope this article helps.