Sudden User Authentication Rejection as a result Compatibility - error

[A.L.M.Buxey at lboro.ac.uk]

Hi,

> Our 802.1x Radius service has run uninterrupted for almost 2 years. Sometime in the morning yesterday, the server started rejecting authentications and Radius log shows loads of Certificate Compatibility problems as below.

sometime in the morning?  what happened on the server itself - patch installed (eg automatic patches via yum-updatesd or such?) 
whats the time/date on the server itself - your cert may not have expired but of the time is very wrong that could throw things
(and does this happen still after a server restart?)

alan