topic EOS R6 Mark II doesn’t connect with lens, Error 01 in EOS DSLR & Mirrorless Cameras

EOS R6 Mark II doesn’t connect with lens, Error 01

anandthiraviyam — Tue, 14 Oct 2025 13:39:42 GMT

Hello

I recently bought canon EOS R6 mark ii. Now my camera doesn’t communicate with Canon RF 24-240, and Canon RF 100-400 lenses. Camera doesn’t show automatic focus option. Error 01 is popping up and it says “communication between devices is faulty. Check the camera lens or other mount adapter contacts. I am able to take pictures. Please help me to resolve this. Thanks.

Re: EOS R6 Mark II doesn’t connect with lens

deebatman316 — Sun, 12 Oct 2025 00:09:23 GMT

I would test both those lenses on a different RF Mount camera. It doesn’t have to be the same camera. All RF Mount lenses are natively compatible with all EOS R series cameras.

Re: EOS R6 Mark II doesn’t connect with lens

stevet1 — Sun, 12 Oct 2025 00:23:34 GMT

anan...,

A couple of questions:

1) Do those two lenses work on any other camera?

2) Does your new camera work with any other lenses besides those two?

It's possible that the contacts on your new camera got damaged or dirty. Have you tried cleaning them?

Steve Thomas

Re: EOS R6 Mark II doesn’t connect with lens

Waddizzle — Sun, 12 Oct 2025 11:25:30 GMT

“ I recently bought canon EOS R6 mark ii. Now my camera doesn’t communicate with Canon RF 24-240, and Canon RF 100-400 lenses. Camera doesn’t show automatic focus option. Error 01 is popping up and it says “communication between devices is faulty. Check the camera lens or other mount adapter contacts. I am able to take pictures. Please help me to resolve this. Thanks. “

Did you buy a new or used camera. Did the camera ever work properly?

Are you using a Canon mount adapter? The first generation of third party adapters seemed to damage many cameras.