When I start SU, when it tries to start the OS plugin, I get "Path to OS Root Directory": I left it in the default c:/OS-version. It comes back with "File 'C:\openstudio-3.5.1/Ruby/openstudio_modeleditor.rb' does not exist. The install then fails. Since lots of the online help appears to be outdated, I assume something like that is happening. I have reinstalled and redownloaded and... SU seems to be working fine otherwise. I do also have SU 2019, should I try to use that with an older OS?