A reminder – firmware updates for cameras happen, and they usually improve things. So I just updated my Canon 1Dx to the latest firmware: link here. I also checked that my 7D (same link) and Fuji x100 were up  to date (link here).

So if you have not updated your cameras firmware recently: check that you have a full battery and a newly formatted (in-camera) memory card, and go google the availability of new firmware.