Ypo writes: > Then could it be a bug? Before the update file: links to a folder > opened it out of emacs. Now it doesn't, even using "attach"'s option > which offers to open links out of emacs.
Which attach option is that? Did you follow Ihor's suggestion of removing (directory . emacs) from org-file-apps? That entry was added to org-file-apps in v9.4 and should explain the change in behavior you're seeing. If that's the case, removing it should restore the old behavior. If that doesn't work, you can try adding (directory . system) to org-file-apps.