Lync Error Code -2146762487

I patched the Lync 2010 environment to the latest and greatest CU5 update yesterday and received this error on one of the Front-End pool servers:

These other services would not start also:

A quick Internet search did not return any relevant results concerning error code -2146762487. An examination of the Lync Server Event viewer logs showed these errors:

I then launched certificates.mmc and found that the GEOtrust intermediate certificate had vanished from the affected server. After importing the Geotrust intermediate certificate into the intermediate certification authorities, all services started and all event log errors cleared.