Hi, I did buy a C5710 recently. I already have five of the same printer and no problem converting it to chipless.
But with this one I am having problems.
I follow the instructions of https://www.2manuals.com/product_info.php?cPath=107&products_id=1940 about uploading firmware
I verify because of "If firmware version is CU26I9 - firmware has been uploaded successfully" part with the WIC Utility and everything is good, version number is CU26I9.
Now the Activation Key I already did buy and downloaded the Licence.exe app, I press Activate Online, paste the emailed code and the App shows Error writing...
I have reinstalled the firmware about three times, verified the instructions everytime. Verified the FW version.