Going nuts here, I had a 2006 Cubase LE program with Tascam US-122l used without issues, purchased Scarlett 18i20 1st time recording it went well sounded great, until I saved project and closed Cubase!! BOOM! BLUE SCREEN of Death, did not save hrs of work lost, Focus rite said the old 2006 cubase my not be compatible,So after trying Live Lite and Reaper, Had to go back to cube base, never used either of those, Got my New Cubase element 7, recorded a session thinking my troubles were over, sounded great love my New cubase, until I saved and closed cubase BOOOM DAMN Blue screen!!!WTF< what is wrong I’am ready to send back the 18i20, Used my old Tascam US-122l, recorded and saved without any problem, so its not the DAW help!!!

Did you go to the Focusrite website and make sure you have the latest driver?

I did, I just purchased it and activated it down loaded the Latest drivers

i would contact Focusrite support. It sounds like a hardware driver type problem. Try disconnecting ALL other peripherals, shutting down ALL extraneous programs, etc. you might also try disabling athe built in sound card. Maybe there is a problem when the system tries to revert to it when Cubase shuts down.