If I run the GotoNova 8400 & SkySafari drivers as a local service from the device manager within KStars, everything works as expected. However, if I run indiserver and drivers from the command line, replicating the command & options exactly as per the process run from the device manager, I get the error as above from SkySafari.
In short, it works perfectly when run from within KStars, but doesn't from without.