Skype for Business CMS Pool Failover Issue

Good Morning All

Last week, while working on a clients deployment one of the Modality team came across a rather interesting issue around failing over a Standard Edition SkypeFB pool pairing.

What started out to be a simple failover test became a monster of an issue without any real good reason. The situation was when the pool faileded over the CMS , it became kindof orphaned in the process with the secondary front end not becoming the master and also what was the primary releasing itself as the master. Its also worth confirming that the procedure to failover was completed without error and issue and it was only when the services restarted that we saw the issue. **The Master replicator service would not start.

As this was the first time of seeing such an odd issue, we referenced the usual channels and came across Mark Vales blog almost detailing word for word the same situation/issue.

Doing some investigation we could see that the CMS was no longer attached to the primary frontend and also the secondary frontend, yet the SkypeFB client was happily working??. Also running powershell commands we could also see that the replication was now false across all the frontends/edge.


We tried a number of steps to resolve this issue including the ones Mark detailed in his blog, without success. It seems this issue can morph itself into many factor.

We tried to failback to the primary without success and got the following error


And when we attempted to restart the services we were getting the following error


Also we went to the extent of deleting the xds/lis databases and reinstalling them and importing the backup we had onto the clean databases. Still we was seeing the same errors.

The solution that worked for us was a simple one really.

Uninstall-CsDatabase –CentralManagement


Install-CsDatabase –CentralManagement

and restoring CMS from backup did the trick.



Northern UC UserGroup 2016 Dates Published.

Good Afternoon All

Below are the Northern UC User Group dates confirmed for 2016.

March 23rd (Wednesday)

June 22nd (Wednesday)

Sept 21st (Wednesday)

Dec 14th (Wednesday)

All the events will take place in Leeds, at the location of Modality Systems Leeds office next door to the Leeds Train Station.

Address: Modality Systems Leeds office: 223 Princes Exchange, Princes Square, Leeds LS1 4HY

Also its with pleasure to confirm for the 2016 events we are running with two sponsors. these being 

Tickets are now available for the March Usergroup HERE