Gaz_Ham many hanks for your suggestion, but the main idea is still to get this fixed on my Mac with the installed HIgh Sierra system. Checking the web i see a lot of drivers issues. Bad thing and not purposeful from Apple, when lots of users are not able to run their equipment.
I have the same problem with High Sierra !!! I can`t install the driver at all, following EXACTLY ALL the instructions from the line6 support page for HIGH SIERRA. Really frustrating...guess I have to go back to Windows :(