I am running Lync Server 2013 and have been running the and Lync for Android 2010 app perfectly fine, as well as Lync for Windows 2010 and 2013.  I just installed the Lync for Android 2013 app and am getting the following message when I attempt to login:

"This version of Lync has been blocked by your system administrator. Please check for updates or contact your support team."

In the Lync Control Panel -> Clients -> Client Version Configuration I have the default action set to Allow.

Also, in the Lync Control Panel -> Clients -> Client Version Policy there is only one entry for AndroidLync and it is set to:
Version: 4.*.*.*
Operation: Older than
Action: Block

I even tried unchecking the "Enable version control" setting in Lync Control Panel -> Clients -> Client Version Configuration

Am I missing something?

Please try to remove MCX agent and run the command Invoke-CsManagementStoreReplication. Then sign in Lync for Android 2013.

Hi 

Check this thread it might help full to you

http://social.technet.microsoft.com/Forums/en-US/ocsedge/thread/f13107b6-1dc3-43c0-a159-202efede29c7/

http://social.technet.microsoft.com/Forums/en-US/ocsmobility/thread/d3d0d742-f1f3-49d3-8637-7753fd2f9edf/

Please try to remove MCX agent and run the command Invoke-CsManagementStoreReplication. Then sign in Lync for Android 2013. 

From what I've read online, it seems that the Mobility Service Agent alias is McxService on the Microsoft Lync 2013 Server.  After removing this I ran the command Invoke-CsManagementStoreReplication as instructed, yet I was still unable to sign into Lync. here are some screenshots displaying my issue.

Try to sign in manually.

https://<ExtPoolFQDN>/Autodiscover/autodiscoverservice.svc/Root for external access

https://<IntPoolFQDN>/AutoDiscover/AutoDiscover.svc/Root for internal access

That is weird. Would you enable the client logging?

I had the same issue, and the solution that worked for me doesn't make sense logically, but it worked.

The default Client Version Policy for AndroidLync was set to BLOCK versions OLDER THAN 5.*.*.*. I simply flipped the conditions to ALLOW versions NEWER THAN OR SAME AS 5.*.*.*, and I was able to log in with Android Lync 2013 app (version 5.0.8563.0 currently)..

As Andrew said,

If you change the default value from Block to Allow, Can you sign in? 

If you cant, check the version installed in your device and create a new rule with the exact version with Allow value.

Hello,

This post helped me:

http://jackstromberg.com/2013/06/lync-2013-android-client-version-of-lync-has-been-blocked-error/

Turned out we had applied Lync CU2 on some of the front-end servers but not all of them in the pool.

/mk