topic Re: Canon EOS R8 firmware upgrade to 1.5.0 failed in EOS DSLR & Mirrorless Cameras

EOS R8 firmware upgrade to 1.5.0 failed

mnrahimi — Tue, 29 Jul 2025 14:51:18 GMT

I have a Canon EOS R8, the current firmware version is 1.4.0.

initially I tried to upgrade it using my iOS CanonConnect App, but when it tries to transfer the firmware after 2 seconds it will say transfer failed, no matter how many times I restarted the camera or phone it didn’t work (image transfer works).

then I tried to use my MacBook Pro M4 with latest OS, I downloaded the Canon EOS utility (the latest available version) that even didn’t start on Mac!

last I downloaded the EOS utility on a windows 11 notebook, it was able to connect to camera using usb cable, but when I try to upgrade the firmware and I’m selecting the downloaded 1.5.0 file it says cannot downgrade the firmware!

can anyone help? What should I do next?

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

nolef22895 — Thu, 24 Jul 2025 13:36:59 GMT

@mnrahimi wrote:

I have a Canon EOS R8, the current firmware version is 1.4.0.

initially I tried to upgrade it using my iOS CanonConnect App, but when it tries to transfer the firmware after 2 seconds it will say transfer failed, no matter how many times I restarted the camera or phone it didn’t work (image transfer works).

then I tried to use my MacBook Pro M4 with latest OS, I downloaded the Canon EOS utility (the latest available version) that even didn’t start on Mac!

last I downloaded the EOS utility on a windows 11 notebook, it was able to connect to camera using usb cable, but when I try to upgrade the firmware and I’m selecting the downloaded 1.5.0 file it says cannot downgrade the firmware!

can anyone help? What should I do next?

It sounds incredibly frustrating, but the "cannot downgrade" error on your Windows machine is a crucial clue. It likely means the firmware file itself is either incorrect, corrupted, or not recognized as an upgrade from your current 1.4.0 version.

Your best next step is to perform a manual firmware update. Go directly to the official Canon support website for your region, download the EOS R8 firmware version 1.5.0 again (ensuring it's the correct file), and copy only the .FIR file to the root of a freshly formatted SD card. With a fully charged battery, insert the card into your camera, navigate to the firmware option in the menu, and follow the on-screen prompts. This method bypasses the apps and utilities, which are often the source of connection or compatibility problems, and is generally the most reliable way to update Canon camera firmware.

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

Pupshead — Mon, 28 Jul 2025 01:42:29 GMT

For me I was using the apps to update past firmware . Problem : the apps don’t delete the old firmware so my camera would not update until I used my card reader and deleted the old firmware from the camera .

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

shadowsports — Mon, 28 Jul 2025 01:53:39 GMT

Agree. What @pupshead said. Firmware is not deleted from the card after an upgrade. Unless removed (manually or by formatting) a new firmware update cannot complete.

To @Danny's point. The safest and most reliable way to upgrade firmware is with a card reader. This allows you to visually check the correct file is copied to the SD card prior to updating.

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

Pupshead — Mon, 28 Jul 2025 02:51:20 GMT

Ha! I could have reformatted the card and then the apps would have worked for the new firmware Thanks !

I guess the card reader method is best if one has important files not copied elsewhere . That could have saved me an hour of bewilderment and frustration !! 🤣 lol 🙏

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

mnrahimi — Tue, 29 Jul 2025 02:37:05 GMT

Thanks for the replies, I would say that’s a bug in Canon firmware, instead of looking at the right file 1.5.0 was picking the old one 1.3.0 that I had on card and was complaining that cannot downgrade from 1.4.0. I hope that either they have already fixed it in current version or they fix it in future version!

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

Pupshead — Tue, 29 Jul 2025 02:48:01 GMT

Yep ! One line of code I’m guessing !

cheers! 😎

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

Pupshead — Tue, 29 Jul 2025 03:16:46 GMT

you have 1.3 on your card !
The camera does not “ see” 1.5 until you :

1) reformat your card

2) use a card reader to delete 1.3

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

Pupshead — Tue, 29 Jul 2025 03:30:27 GMT

Your camera still has 1.3 on the card !

Reformat ( initialize ) the card and try again

let me know ! Thanks

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

mnrahimi — Tue, 29 Jul 2025 12:14:54 GMT

There were both 1.3.0 and 1.4.0 still on the card. I always was using the CannonConnect app for the upgrade before.

Re: Canon EOS R8 firmware upgrade to 1.5.0 failed

Pupshead — Tue, 29 Jul 2025 12:48:06 GMT

me too . Now a bug in the code stops 1.5 from updating if 1.3 is still on the card .