Many thanks Angel. Your suspicions sound solid here as I have received some Debian updates recently about potential issues with the X server. I didn't pursue them to see if this was something that might impact me. After looking at your advice, some dots have just formed and connected for me. Especially the fact that the windowing systems crashes and I get logged out at the same time. Perhaps it is purely just co-incidental that Evolution was the only application that I was running each time this happened and Evolution had nothing to do with the crash and being logged out of Debian. I'm going to go back to the Debian security updates I received in the past regarding X server and follow up. -denni On Wed, 2020-12-02 at 00:06 +0100, Ángel wrote: dmesg |