When I click on open all in new tabs command in settings, the links open in new tabs but have also started opening in separate new windows as well . If I delete/close a tab, the corresponding window will close. If I close a window, the corresponding tab closes. If I close the tabbed window, all of the otehr new windows close, but if I try to reopen Firefox I get the Firefox is still running message. Once I click on close, I can reopen Firefox. I am running on Windows 10 (fully updated) on a laptop PC. This has only just started. I have the open links in new tabs setting enabled????????