I keep getting the Err 05. Different from the other inquiries on this site, my flash pops up and is not stuck. However, it does this even in the sunniest of days when I don't need the flash. It then clicks and won't allow me to take pictures (after the flash is up). It is extremely annoying, as I am taking action shots and need the continuous setting, but because the flash is waiting to set, it delays the picture taking too. It will happen over and over again. I do what it says, turn it off and on again and pop the battery out. It is quite annoying and VERY frustrating!!!
Sorry to hear about your problems. It appears you may need to send it in for service.
Not sure which camera model you have but in general, you should be able to set the option to never use flash (either on the mode dial and/or via the menu option). I'd do both.
You should try disabling the flash and see if you can avoid the annoying problem.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.