Overlay scrollbars disabled on upgrade - how to reenable?

Question

When I upgraded from Natty to Oneiric and then immediately to Precise, for some reason the overlay scrollbars stopped appearing. They were enabled and worked just fine in Natty, and are still enabled in theory. I've purged and reinstalled these packages: overlay-scrollbar, liboverlay-scrollbar-0.2-0, and liboverlay-scrollbar3-0.2-0. That did nothing. I also tried using both Ubuntu Tweak and Unsettings, but both showed that overlay scrollbars were turned on (and turning the settings off and back on again did nothing either).

Any ideas how to get them back? Thanks!

Edit: I just read that some people disable them by adding a line in ~/.xprofile or /etc/X11/Xsession.d/99disable-overlay-scrollbars, but those files don't exist.

Answer 1

Linuxicle explains how to enable and disable the overlay scrollbar in easy method.

gsettings reset com.canonical.desktop.interface scrollbar-mode 

Answer 2

I found a file called 80overlayscrollbars in /etc/X11. Despite the filename, it had the line export LIBOVERLAY_SCROLLBAR=0, so it was actually disabling them. Since I never changed the defaults, I really wonder why the upgrade process managed to disable them.

Answer 3

Try installing dconf Editor from the Ubuntu Software Center. It has an option for enabling/disabling overlay scrollbars. The option is located under the following subfolders(click triangles to open) org> gnome> desktop> interface. In the options pane the last item in the list for interface options is ubuntu-overlay-scrollbars which has a checkbox. Click a checkmark in the box, close dconf, log out/in, and it should work.

I often switch appearance themes to high contrast and back which seems to lose the scrollbar setting.