URGENT - Cortex Issue

We cannot download the program to the Cortex. We have tried all troubleshooting measures. These parts have been swapped for known working parts - Cortex, Serial Link, Primary Remote, Keys, and added a backup battery. Current Error message with Cortex directly connected to the computer is: “Failed to verify the serial link is connected to a robot controller. Cannot communicate with VEX Cortex Slave CPU. Master CPU communication is working.”

All batteries are freshly charged. Please help!! Tournament is in a few hours.

Additional error: Flash write failure. File in robot is corrupted needs to be downloaded again.

Hello Kowens,

I suspect those error messages are being caused by a very simple problem…
Are you running easyC or ROBOTC?
Also please confirm the version of the software you are running.

I await your response.


We are running RobotC 4.10


Thanks for the confirmation.
I recommend a manual update on the ROBOTC firmware of your microcontroller. Please refer to the attached screenshots.

Let me know your results.

Doc1.pdf (229 KB)