I most often work offline on a Win PC laptop/tablet.
It appears that Painter 2018 refuses to fully load unless connected to the internet.
It just sits showing a big white box. No controls, menus, tools work when in this state.
Can someone confirm that this is true?
Answered my own question...
Within that big startup screen with all options for default workspace, icons to buy more stuff etc. there is a little gear at the top right which when clicked has a "show this at startup" checkbox. Just uncheck the box and Painter starts fine without being connected to internet.