My D800E does not reliably trigger remote flashes, in TTL mode or otherwise. There is a known bug with M mode. That can't be my problem because switching to TTL is supposed to avoid it. If anything the problem is worse in TTL mode. I initially thought it never fired remotes that were set to TTL but with more testing I got occasional fires. When it does trigger remotes the camera flash usually does not contribute any illumination itself.
Used in normal mode, rather than commander, the flash usually works. After the first CLS glitch the flash never charged (no lightning bolt symbol) and I had to remove the battery to get it back. That problem did not recur.
Anybody have this variant of the problem? I hope I just forgot to set custom setting Q39, "Enable random CLS failure", to Off.
I tried different slave flashes, SB-800 and SB-R200. I checked the SB800 with a different camera. It's the camera, not the flash.