You will see the above error while implementing persistent chat. To fix this error, we went around in circles and finally we were able to fix this permanently.

There is no single problem that can bring this error.There are so many factors that can cause this persistent chat functionality to break.

In this article, we will see a few factors that can cause this functionality to be broken.

Below is the error message that you will get when you try to enable PC functionality.

PCe

Following below factors can cause the above issue:

1. Issue with SQL database connectivity:

First, check the SQL database that the persistent chat has been created successfully. If you get any warnings related to SQL when you publish the topology for persistent chat then you shouldn't proceed with the setup. Connect to the associated instance from your SQL backend DB and check if the DB is created for the newly introduced PC role. If you don't see anything then you need to first fix this issue.

Note: Also make sure the below configurations are set correctly on the FE, PC and SQL backend database server for a successful SQL DB creation.

a) Make sure the port number 1433 is open between PC role server and the backend SQL. You can telnet to port 1433 and vice versa from SQL back end to PC and check the connectivity.

b) You need to have network discovery and enable file and printer sharing option to in both servers in order for the connectivity and vice versa.

c) Make sure that you have the sa (super admin) rights on the SQL instance or the server where you are trying to create the DB for this new server.

2.  Once you publish the persistent chat server from the topology builder you need to run the Lync deployment wizard.

ldw

Just run the first two steps alone to install the PC component roles and update them.

3. You can run the below command to set the persistent chat servers. Although this is not a mandatory step but at times even this can cause this problem. So it's better to run this command from Lync management shell.

Set-CsPErsistentChatActiveServer NAME -ActiveServers @{Add="NAME_OF_PC_SERVER"} -v

4. Make sure you have the latest Cumulative Updates installed on the PC server. In my case, this was the issue. So as a rule of thumb it's always better to look for the latest CUs in the persistent chat server. Also, make sure that the persistent chat services are running fine on the PC servers.

5. Final step is to go back to your Topology Builder, delete the Chat Pool and rebuild it if none of the above works.

Delete the chat pool that you have created from the topology builder. Then go to your deployment wizard and run install or update server system and setup or remove Lync server components.

Following the above troubleshooting steps will most likely bring up the persistent chat channels in an environment.