Wireless tethering is critical to our Architectural photography workflow. However on a recent photoshoot I needed to use a backup 6D instead of the usual 5D and was surprised when CamRanger refused to tether with it. From what I've experienced with CamRanger and knockoff (TPLink router hack) they're bulletproof and work with any Canon or Nikon camera. Not on this day of course... The solution turned out to be super simple but I wasn't able to find it mentioned anywhere online - so I'm posting it here in the hopes that future google'rs will find the answer they need.
If you're unable to connect CamRanger or DSLR Controller/TPLink router to your Canon 6D and you've followed all the instructions, green lights are on, etc and you're out of ideas then I have a solution for you. Drumroll please...... Disable WiFi on the Canon 6D. Yep. Evidently if WiFi is enabled on camera it blocks out the ability to tether via the camera USB port which is what CamRanger / TPLink router need to function.
That's it. Super simple solution - disable WiFi on your Canon 6D and CamRanger will work like a charm.