Product:
Cognos TM1 10.2.2 Fix Pack 6
Cognos BI 10.1.x or Cognos BI 10.2.x
Microsoft Windows 2012 R2 Server

Symptom:
When try to create a data source connection to a new setup TM1 10.2.2 server (with fix pack 6) from an old Cognos BI server. You get an error.

Error message:
DPR-ERR-2072 Unable to load balance a request with absolute affinity, most likely due to a failure to connect to the remote dispatcher. See the remote dispatcher detailed logs for more information. Check the health status of the installed system by using the dispatcher diagnostics URIs.

Or
Failed
XQE-DS-0006 Unable to logon to the data source.

Solution:
Then it can be that the TM1 instance is configured to use the CAM login from a different Cognos BI installation than the one that you are creating the request from.
You need to ensure that the CAM connection in TM1S.CFG point to the same Cognos BI server as the one you run the Cognos BI report on TM1 data from.

If TM1 authenticate to Cognos BI server A ,and you try to connect from a different Cognos BI environment Cognos BI server B (that have it own content store) you can get errors like above.

Change the values for CAM and restart the TM1 instance.
ServerCAMURI=http://serverB:9300/p2pd/servlet/dispatch
ClientCAMURI=http://serverB/ibmcognos/cgi-bin/cognosisapi.dll

Also make sure that the Windows Firewall has the needed ports open:
5495, 5498, 9300, 9510, 12345, 12346

The last ports are for the TM1 application (planning sample) you need to add your ports in for your TM1 instance. Check in the TM1S.CFG file for each TM1 applications port number used.
PortNumber=12345

If you enter a ADMINHOST=TM1serverC or not does not matter.
ClientMessagePortNumber= are in most cases not needed, but is recommend and then needed to be added to the list of open ports in the firewall.

More info:
http://www-01.ibm.com/support/docview.wss?uid=swg21586113