on OSX, if a cell contains a link:
if you click on it, nothing happens. (not opened, not edited)
if you hover over it, a tool tip says: "control-click on the link to open it"
if you control-click on the link, a context menu is shown instead.
the context menu does not contain an entry to open the link.
Use Cmd-click instead - this is an error in the tooltip text which does not take into account specifics of Mac shortcuts, but has been resolved in
*** This bug has been marked as a duplicate of bug 87863 ***