Hi Barry,
The COM_TI_RTSC_TIRTOS_INSTALL_DIR is a variable set in CCS by TI-RTOS which has the directory where TI-RTOS was installed. For release 2.0 and above, TI-RTOS was split to have individual installers for each device family (Tiva, MSP430, Sitara, etc). The variable has been renamed for each individual product; for example for TI-RTOS for Tiva it is renamed to COM_TI_RTSC_TIRTOSTIVAC_INSTALL_DIR.
The reason you are seeing the link error is because you started your project with release 1.21 and still pointed to old paths. The application will compile correctly if you modify your project include and linker paths to use:
Hope this helps,
-- Emmanuel