Today I had to reboot my Jessie system, after Firefox totally hung the system (for over an hour, with 20 tabs open). After the reboot, it seems that most things are working (well, the things I can test without a mouse), but the mouse is not working.
The Jessie system is connected to a KVM system, and because I had to run some errands, I started the boot process and then left, with the KVM set to the Jessie system. When I came back and tried it, I found that the mouse is not working. The mouse still works on the other two systems connected to the KVM switch. I've tried googling and looking at (and trying some) commands found with apropos mouse or apropos x (a lot), but I haven't found a way to activate the mouse. (I'm assuming that if I reboot and mouse around early after the reboot, the mouse will be activated, but I'd like to avoid another reboot, and maybe learn something.) While I was looking for ways to activate the mouse, I did come across a place where I could click (well, via a keyboard shortcut) something that said something like: "activate mouse with KDE" -- maybe at some point in time I fat fingered something that unchecked that? Anyway, suggestions appreciated. I have tried to get to the "system settings" ahha, ok, I can type systemsettings at a CLI as user, but (1) I don't know how to navigate within that page to get to the mouse device, (2) but (on another system), although I see things to change about the mouse under Hardware ==> Input Devices ==> Mouse, I don't see anything that appears to activate (or de-activate) the mouse. Suggestions appreciated.