I decided to get the R5 as I'm primarily a wildlife photographer, especially birds in flight. I've saved for nearly a year to be able to afford it. The new camera arrived the other day and I spent a few hours familiarising myself with it and configuring the menus. During the first few test shots in the back garden, Error Code 70 happened. This occured at random about 7 times during an hour. The problem didn't arise again during the remaining 20 minutes of test shots. Today I was able to get out and test it in the field. I shot mainly action wildlife and birds in flight. Disappointingly Error Code 70 happened, I would say about 15% of the time in a three hour session. On one occasion I had waited for a Copmmon Tern to return with a fish in its beak to its chick. I tracked the bird and pressed the shutter just as it approached and got Error Code 70! Missed the entire sequence of shots. I have brand new CF Express and fast SD cards. From what I've researched, Error Code 70 is supposedly a relatively rare occurence, with the 'blame' being placed on either insufficently fast cards or poor connections to the lens or even potential motherboard issues. I had already updated the Firmware to 1.15.2. I just don't get how a brand new camera (for me) that has been available for two years now can have such problems. Any advice would be welcome, but at this point I can't help feel that the product will have to be returned. Unfortunately, the 14 day money back guarantee seems to only apply to new, unused. Well of course I had to use it to discover the problem!