Hi Jim.
I had the same issue, during the project transfer from CW 7.1 to 7.2.
The solution:
I just replaced the CW 7.1 Target Initialization and Memory Configuration files (M52259EVB_INTERNAL_FLASH.cfg & M52259EVB_INTERNAL_FLASH.mem) by the files from the CW 7.2 generated example project. After that I can erase and program the flash memory without any error.
Best regards,
Andrey Butok