Hopefully this is an easy one, but I can't find it. Suddenly I need to double click instead of single on a sketch or feature to see/change the dimensions. Also if I draw one line, I need to give the "line" command again to draw another one. It is not modal anymore. The same goes for dimensions and other sketch entities.
Is there a way to lock the options/settings so they can't change until I unlock them? It seems like once or twice a month "Enable Confirmation Corner" becomes turned off and I have no idea why. "Automatically Load Components Lightweight" inexplicably becomes enabled once in a while too.
"Suddenly I need to double click instead of single on a sketch or feature to see/change the dimensions."
I assume you mean this is while you aren't in any active sketch or command? If yes, then "Instant 3d" has gotten turned off.
"Also if I draw one line, I need to give the "line" command again to draw another one."
That sounds like the setting indicated below has gotten turned on.
I'm not aware of any way to lock user settings, but you can use the Copy Settings Wizard to save them and reload when needed. See Can I save my SolidWorks settings for when I upgrade, or to share with another user?.