Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

[arabicsnus]

Hello guys!

I upgraded my camera to the latest software (Canon R7 - FW 1.6).
Since then it does not recognise my lens (Sigma 120-300 2.8 sport).I used it the day before to shoot a football match. I have tried other lenses since then and it worked (Sigma 18-35 1.8, Sigma 50-100 1.8, Canon 18-55 kit lens). I have two very old cameras (Canon 400D, Canon 7D mark I) and I tried it on them too but the 120-300 lens worked perfectly. Has anyone experienced a similar phenomenon? 

Best wishes, Gergő

[ctitanic]

Err 01 is an error code that appears on Canon cameras when there is a communication issue between the camera and the lens. To fix this error, you can try cleaning the electrical contacts on the camera and lens with a clean, dry cloth.

[ctitanic]

Also, you are not the first one reporting issues between that lens and the R7.

https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/EOS-R7-won-t-recognize-Sigma-120-300m...

We concluded in that thread that the odds of finding a fix are minimal.