topic Re: EOS R5 Mark II "Card 1 Full" Error in EOS DSLR & Mirrorless Cameras

EOS R5 Mark II "Card 1 Full" Error

ashtynschaefilm — Mon, 24 Aug 2026 17:10:28 GMT

Has anyone experienced a false “Card Full” error while recording video on the Canon R5 Mark II?

I’m a wedding videographer and this has now happened at two weddings in a row since getting this camera. I record simultaneously to two 128GB cards (CFexpress + SD). The camera will randomly stop recording and say “Card 1 Full,” even though the cards only have around 30–40GB on them and have plenty of space remaining.

At my last wedding, I removed the CFexpress card (Card 1), switched from dual-card recording to standard/single-card recording on the SD card, and it recorded normally for the rest of the night.

Has anyone else experienced this or figured out what causes it? I need to be able to reliably record to two cards without the camera randomly stopping during a wedding.

Re: EOS R5 Mark II "Card 1 Full" Error

Ian_D_Head — Mon, 24 Aug 2026 20:04:56 GMT

I can't answer your question but; have you tried another CF card, sounds to me like you have a faulty one. It would stop the camera if it can't write to one of the cards when set to use both. The fact it records OK to your SD card points to it being that.

Re: EOS R5 Mark II "Card 1 Full" Error

Waddizzle — Mon, 24 Aug 2026 20:14:25 GMT

How many video clips are in the folder? I think there may be an upper limit.

Re: EOS R5 Mark II "Card 1 Full" Error

Ian_D_Head — Tue, 25 Aug 2026 07:30:18 GMT

I’ve just read that there’s a firmware bug that causes exactly what you describe, if you’re using firmware 1.2.0 I’d suggest you update to the latest, which is 1.3.1 right now. Otherwise, check if you have hit the 999 file limit as mentioned above. But I would have thought this would affect both cards. Then still leads to a possible faulty CFexpress.