Not saving and not responding

Last night I was jamming and got a nice melody going. So I just recoreded it straight into Cubase and pressed save and wanted to close Cubase down and go to bed. It seemed to save the file ok so I pressed quti to close down Cubase and go to bed. I froze with the top ribbon up and all windows closed. Stopped responding so I had to kill it from the eventhandler in windows10. Open up Cubase now and wanted to continue working on the track. IT WAS NOT SAVED! So it was gone. Really hate this bug.