Thanks for the response. Sorry I should have followed up sooner.
I was running Xubuntu on a Chromebook and it just wouldn't launch for some reason. So I installed GalliumOS instead and Dotgrid now runs!
I was having trouble altering the size of the grid because I normally do this thru the menu on Mac OS X, and there is no menu present on the Linux version ... however I see there is a shortcut (Cmd+E) so I'll try that out tonight.