Firmware updated, working good so far.
are you on Mac? I heard pc is not ready yet
Since the majority of us do not have a 1DX, 5D3, or 650D - remember the simple means of avoiding this issue are: Turn your camera off first before putting the lens-cap on
Alternately if the issue happens - its said you can quickly take your battery out and pop it in again - or - detach & re-attach your lens. (power off?)
As of yet the issue has only happened 1x for me in 2 months, but having the power off when putting the cap is easy to remember.