cmd: 'vex iq stop pgm' errro: no reply received

good day, sir! I tried updating the vex iq firmware, as it was prompted and was taught during the troubleshooting, however, the vexos utility sometimes can no longer recognize the brain and keeps prompting to install. moreover, when i tried graphical c, it doesnt download firmware and shows error message: cmd: ‘vex iq stop pgm’ errro: no reply received. i was able to update the vex iq firmware but that’s it, this is what happened.