CCS v3.1 "Error, Don't know how to build file"

I recently uninstalled and reinstalled CCS 3.1 because I could not flash my target. Since reinstalling, when I open my project, all my .c and .h files are in the "Documents" folder and not in the "Include" and "Source" folders. Also, when I select Project->Add Files to Project, the "Files of type" field will not let me select *.c or *.h files. When I specify "All Files (*.*)" and open a c file, it puts it in the "Documents" folder.

When I try to build, rebuild all, or compile any files in my project, the error I get is: "Error, Don't know how to build file." Before I uninstalled, I could build successfully and didn't see any of these issues. I suspect I made an installation error or missed a step. Any ideas what it could be? I've uninstalled and reinstalled 3 times now.

Thanks so much,

Nick