just noticed that you've unchecked "show caption" on your foobar and i personally dont know of a way to enable it back without other captions since the only way i know of adding/removing panels is though rightclicking on the caption.
try installing
This over your current foobar and see if it fixes the problem, if it doesnt then uninstall and install this copy (make sure to uncheck components you dont needs cause thats the special installer)
EDIT: actually theres a way to reset the sidebar under preferences/columns ui, i still recomend installing this over your current foobar though since its the most up to date installer (with ~5 days margin of error thanks to Case

)