Tethered EOS 5D Mark IV freezes with memory card, Lightroom requires card

[Aleix]

Canon 5D Mark IV tethering issue on MacBook Pro M4: camera freezes with memory card inserted, Lightroom doesn't detect camera without card

[ebiggs1]

The CF/SD card does not need to be in the camera when tethered to Lightroom. The images are transferred through the tether cable to your hard drive. Tethering is a hot topic here on the forum but I have never had an issue with any of my 1 Series tethering to LR on a Windows laptop. You should be able to shoot without a memory card installed.

I did not have a 5D Mk IV but I did have a 5D Mk III which I also tethered to LR same setup without issue. This leads me to believe in your case the problem is either with your MacBook Pro M4 or the tethering software or your USB cable. I always use active USB cables so length isn't an issue but if you have a long USB cable that can be the problem. Try to keep it under ten feet.

What app are you using on your MacBook Pro M4? I recommend you get Lightroom Classic. (Lightroom CC does not support tethering.) The MacBook Pro M4 could also be the problem can you try a different computer? 

[Waddizzle]

There’s a setting in menus somewhere, “ Release shutter without memory card”

I think it’s disabled by default.