When I click the program browser, the list comes up, but when I try to select one, I get the following message:

IDS_FILE_MISSING not found in text resource file

I can load the programs from the program menu. The files are in c:/program files/VST Plugins/Session Drummer 2/Contents/Programs...

Do I need to change a pointer somewhere?

Any suggestions?

I have the very same problem.  It happened after I reconfigured my hard drives following installation of a solid state drive.  The letter name for my system drive onto which Sonar is loaded was formerly D and is now C.

Anyone have any idea how to fix this?

During installation most software, SONAR included, rely on the drive letter when writing data into config files and the registry. Changing the drive letter of a drive after software installation is usually catastrophic to program operation. I am surprised that only Session Drummer 3 is failing. In any event, here is a link that details all the Cakewalk synth registry entries including Session Drummer 3 http://forum.cakewalk.com/fb.ashx?m=2673527