Two weeks ago I was trying to tether the Leica SL2 to Lightroom Classic for a photo shoot. Every time I launched "start tethered capture" in the app it would crash. Something has changed. I have no clue what it is. But the process is now simple and saves me from buying yet another expensive and unnecessary application which I would have only used for the purposes of tethering a camera.
Here's how to do it. First update both the camera, the computer operating system and Lightroom classic to the latest versions. In the camera menu choose PTP for your USB setting. Turn off camera. Attach the camera to a USB 3.0 cable and attach the cable to the computer. Launch Lightroom. Turn on the camera. Select "tethered capture" in the LRC "file" menu. Select "start tethered capture" in the sub-menu. Select a folder to house the files. Start shooting.
This works with the camera's raw files because they are a standard .DNG file.
A window will open at the top left of the screen to show a preview image. You can use a command bar to do rudimentary setting changes on the camera and to trigger the shutter. When you take each shot it appears in the center screen at a large size. A row across the bottom of the window contains the sequential thumbnails of all the images. You can magnify the selected frame and use any other image processing tools in Lightroom. You do not need to load any plug-ins.
I tried it twice. Both times it was rock solid. Nice. Happy photographer.
Now to see if it will work on an older SL....