Please check out this article Fix tethered shooting in Lightroom where we have documented possible causes and solutions of the problem you are facing.
Also, ensure that a card must be in the camera for tethering to work properly with this camera.
Let us know if that helps.
Yes I went through all of those steps. Still not working properly. Works fine with capture one but I would like to use lightroom.
1 person found this helpful
That did not work as well. Made it worse. When starting the tether it flashes on and off that it's reading the camera. Tether works perfectly fine in capture one so it's not the cable. Canon 5D mark iii works fine in lightroom. For whatever reason the 5D mark IV does not work with it. You should take this camera off the list of cameras that work with Lightroom.
The result from my testing: In the very opposite way, take OUT both the CF card and SD card from 5d IV, tethered capture works perfectly fine.
I am running Lightroom Classic CC (7.0.1) on MacBook Pro, macOS High Sierra.
But when I put any card into the camera, the picture can not write into the card while tethered, that cause the issue.
I also tested with EOS Utility, when I choose save to "computer only", it works fine; when I choose save to "camera memory card only" or "computer and camera memory card", they both don't work. I can see a red line error information said "connection lost".
The camera shows a computer logo on the screen as the error with Lightroom Classic CC tethered.
I hope it does help.
I have had the same issue with Canon 5d mk IV. The solution for me was disabled ftp (automatic transfer - off) and wireless in the camera settings. When I turned it off, tethered start working. Good luck!