Upgrade to 4.22 issues

I recently upgraded the firmware to 4.22 for the joysticks and cortexes, and we are unable to tether any of these components. All the batteries have been charged and replaced, yet we are continuing to have this issue. Any recommendations for a quick fix would be GREATLY appreciated!! We have a total of 7 pairs, 6 of which were upgraded (and do not work) and only one pair that wasn’t, and this is working fine. Thanks in advance for your replies!

Hello Stephen Cousins,

The firmware you are running (4.22) is outdated and might be the source of your problem. Are you using programming software? easyC or ROBOTC?

Please confirm.


We are using Easy C4 for cortex version I looked for an updated version (4.23 ) but it says I am up to date.

I just checked for updates again, and we are at the current version according to the updater. We have been unable to control our robots since mid February, except for the two we did not update.

Stephen Cousins,

4.23 is the correct version of the master code. Please use the* IFI VEXnet Firmware Upgrade* to update your Microcontroller & Joystick.
Screenshots attached.

Let me know once complete.

Screenshot.pdf (261 KB)

Eli Osorio,

Thank you for your response. This is exactly what * did last time and it only upgraded to 4.2.2. This time it upgraded to 4.2.3, and the initial test of the first two controllers and cortexes are reassuring positive. We will have the rest of the controllers tethered and tested tomorrow morning.
Thanks again - though I am not sure why the 4.2.3 upgrade did NOT happen lat time I tried to upgrade.


Sorry, Eli Orsornio.

Again sorry, Eli Osornio.

So all controllers and cortexes were upgraded and attempts to tether them were tried We were successful in only 2 pairings, while the rest continued to not talk to each other. We are in the process of rechecking our batteries, as many of the 7.2 volt 300 aAh NiMH power packs seem to not be holding charge well. We are in the process of charging our 7.2 V 200 mAh NiMH power packs, and will try to tether again tomorrow.