It's also possible the web cache for the viewer has become corrupted. I'm not sure this gets cleared between viewer upgrades, so best to try clearing it manually.
Delete the contents of both of these folders:
C:\Users\[Computer Account Name]\AppData\Roaming\SecondLife\browser_profile\cache
C:\Users\[Computer Account Name]\AppData\Roaming\SecondLife\[SL Account Name]\browser_profile\cache
Then log in and try search. Hope it helps.