There are two ways forward:
- Update GRBL to a newer version that’s compatible with the latest version of Carbide Motion. Requires some degree of comfort with flashing microcontrollers, but here’s a reference to a previous case: GRBL update from 0.9 to 1.1
- Use an older version of Carbide Motion that’s compatible with an older version of GRBL. See: Downloads and scroll down to v3.