If I click on the file I want to open while RSD is open already, the file opens in another instance of RSD. I've had up to three such instances running at the same time.
As I said ... it' like the 80's all over. On a Mac however there's no such thing as an instance. So it's closing one document/project in order to open another.
And when I close a project, and via Menu > File > New ... start another, nothing happens. Until I switch to another app (or Finder) and then back to RSD; then the requested new project appears (this behaviour obviously is a bug).
Ontwerpzaam | Papendrecht, The Netherlands
27" iMac i5 3.1GHz / 32GB RAM / 4TB SSHD / 1GB VRAM - macOS 10.12.6 Sierra
Switched from Softpress' Freeway to Coffeecup Responsive Design software