Another follow-up. Had the same problem with 20.04 amd64. My solution detailed above would not work when using the GUI where the Blueman bluetooth applet was in the notification area.
Eventually I found it worked from a real tty console (switched from GUI to tty2 with Ctrl+Alt+F2) and running the bluetoothctl sequence as detailed. ** Summary changed: - [Regression] 16:04 + 15:10 - Cannot pair with devices using (legacy LMP Link Management Protocol) PIN codes + [Regression] 16:04 and later - Cannot pair with devices using (legacy LMP Link Management Protocol) PIN codes -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1490347 Title: [Regression] 16:04 and later - Cannot pair with devices using (legacy LMP Link Management Protocol) PIN codes To manage notifications about this bug go to: https://bugs.launchpad.net/bluez/+bug/1490347/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
