TMS320F28377D: ePWM variable error

Hello,

I have been unable to successfully track down this error. I have one code set that works and one that does not, and I can't tell the difference between them. The error is

"unresolved symbol _ePWM, first referenced in C:\ti\c2000\C2000Ware_4_00_00_00\libraries\calibration\hrpwm\f2837xd\lib\SFO_v8_fpu_lib_build_c28_coff.lib<SFO_v8_fpu_lib_build_c28.obj>"

and the map shows....

n/a   UNDEFED   _ePWM  

Any thoughts on where to look?

             Thanks

                 Dave