I just had to reinstall Windows on my computer after a Windows 10 patch crashed my computer. All of my applications were uninstalled. After reinstalling Firefox, shift-click (and ctrl-shift-click) do not work.
It's very weird. My suspicion is that I accidentally changed a setting in about:config or it was changed for me.
I've tried opening Firefox in safe mode (i.e. disabling all extensions) yet the problem remains. Is there any way to fix this? Thanks.