I have been using R6 for many years till I decided to have a llok at R7 evaluation.
Unluckily,R7 crashed each time I tried, so I uninstalled it.
Right after R6 doesn’t start anymore, I checked my license at Rhino Account and disable the R7 evalto be sure of no conflict but nothing better…
Help
If you go to Windows Programs, find Rhino 6 in the list, right click and choose “Change” and then in the dialog that comes up punch the “Repair” button - does that fix anything?