Communicator 2007 R2 Client will not Sign in after applying update

I deployed Windows Updates to our domain last night and our communicator clients will not connect. The Update i applied was KB 2028888. The error that i am seeing is:

Cannot sign in to Communicator. You may have entered your sign-in address, user name, or password incorrectly, or the authentication service may be incompatible with this version of hte program. If your sign-in information is correct and hte problem persists, please contact your system administrator.

Is there something i would need to do on the OCS serve side of things to enable this new update?

Should i try and decline the updates (only on 10% of computers right now). ?

Thanks
RavenIndAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

flashinglemurCommented:
Three suggestions:

- Can you restore the PCs before the update?

- Or totally uninstall/reinstall client.

- Or, do not install and wait for newest Communicator.  I'm beta testing it now and should be out shortly.  It will have a new name, but offer increased functionality and stability.
RavenIndAuthor Commented:
The issue was a Group Policy that was changed over the weekend to allow for Kerberos security. Once the GPO was removed everything now works. I will have to do some further research on this to figure out why it wasn't working with Kerberos enabled.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Windows 7

From novice to tech pro — start learning today.