Keyboard shortcuts stopped working yesterday. Copy/paste still works, and tab, but for example ctrl-f (find), ctrl-b (open the bookmarks sidebar), alt-arrow for next/previous, ctrl-w (close tab), etc no longer do anything. Any ideas why that might happen?

This is not the only thing that broke yesterday (e.g. context menu text no longer appears except for icons and some plug-in items) but I don't know whether that is related.