Description:
With r12.1.1 Microsoft Project (MSP) 2010 is supported and the install process has changed compared to pre-MSP2010 versions.
Solution:
The documentation "CA Clarity Project & Portfolio Manager Using CA Clarity PPM with Open Workbench and Microsoft Project" guide for r12.1.1 specifies in chapter 3 under "Set Up Microsoft Project with CA Clarity PPM Microsoft Project Interface" that MSPAdd2k.MPP needs to be double-clicked to install the Add-in for Clarity in MSP, however, this is only applicable for MSP versions prior to MSP2010. For MSP2010 this step is not required and the Add-in is automatically installed with the setup.exe (available under c:\Program Files\CA\Clarity\CA Clarity PPM MSPInterface\addIn after downloading from Accounts Settings).
Some customers - specifically under Windows 7 - have used the following alternative install for MSP2010 - Clarity 12.1.1 connector.