I can confirm the bug on 16.04, but it's only nautilus/GTK reporting the file type is "Amiga SoundTracker audio (audio/x-mod)".
In a shell it is correctly identified as text: $ file Untitled\ Document\ 1 Untitled Document 1: ASCII text Furthermore, the bug does not seem to exist any more in Ubuntu 18.10. ** Package changed: gedit (Ubuntu) => gtk+3.0 (Ubuntu) ** Changed in: gtk+3.0 (Ubuntu) Status: New => Fix Released ** Also affects: glib2.0 (Ubuntu) Importance: Undecided Status: New ** Changed in: glib2.0 (Ubuntu) Status: New => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1778962 Title: when entering the line of text "if network manager is crashing you can restart it with sudo systemctl restart network-manager;" the editers saves the file as a Amiga SoundTracker audio (audio/x-mod) file. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/glib2.0/+bug/1778962/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs