Can't Delete Extension with Small "X" Action Button

In extensions module:
Small "X" action button at rightmost column of Extensions list has no effect. Can't delete an extension with this small button.
Note: "Edit" icon next to it does work. Larger "X Delete" button above the list also works (after checking box for extension). The small X seems to be the only button that does not work.

Issue is in both Chrome and Firefox. Cursor changes as if there should be a link, but no action occurs.