How do I make SnapGene reopen or forget the open Project, or open Tabs after restarting?
By default, upon restart SnapGene will "continue where you left off" and will reopen your Project folder and any previously open tabs in the main SnapGene window.
Open Preferences
Click menu SnapGene → Preferences (macOS) or menu Edit → Preferences (Windows or Linux), and select "Files & Tabs" in the sidebar.
Check the option "Start with an empty workspace" if you want SnapGene to forget the open Project folder, and forget all previously open Tabs, after Exiting/Quitting SnapGene.
SnapGene will remember all open tabs associated with a Project folder. Check the option "Restore previously open tabs" to have open tabs restored if you close the reopen a Project Folder - see Use the SnapGene Project Interface.