The new Canon EOS 90D does not work with tethering in Lightroom 9.1. The Canon EOS 70D and 80D do work perfect. The 90D works fine in other software. Maybe the correct Canon SDK.DLL needs to be renewed or updated? Does anyone have a solution?
I have now found the solution. In the Lightroom folder I have replaced both canon dll's with the newest dll's from the canon development website download. Name DLL: EDSDK.dll and the edsImage.dll Existing version 188.8.131.5200 Adobe in 184.108.40.20600 from Canon SDK and tethering in Lightroom 9.1 now works with the Canon EOS 90D.