I have also posted this on the canon forum and it was suggested to post on this as well.
I have just uploaded some video from my Canon XH G1 to final cut pro x. After uploading all seemed fine with browsers clips a bit slow and jerky but was happy with that. I started to edit and place clips in the timeline and noticed that the clips were not rendering automatically although it was set up and had been working in the past with no changes to FCP X. Each clip had to be rendered with Ctl R. too render it. After a few experiments reloading FCP X twice on two computers still the same.
Apple was very helpful to me and tried to help as much as they could. We uploaded from and iPhone and that worked fine. I decided to load all the clips into the timeline in any order and then from the dropdown menu rendered all. I then place all clips back into the browser and as they had all been rendered all worked well.
My question is it as Apple said my camera has now become incompatible with FCP X now and will need to purchase a new camera. I see on this forum a few are still using the camera have they found a way around it or do I carry on as I am doing.
iMac (Retina 4K, 21.5-inch, Late 2015).
3.1 GHz Intel Core i5
8 GB 1867 MHz DDR3
FCP X 10.4.6