This might be fullscreen direct scanout, which happens when a window is maximized on a monitor that has no panel or dock. Please try unmaximizing the window and just dragging it to the second monitor as a regular window. This should also help to work around the problem:
gsettings set org.gnome.nautilus.window-state maximized false But it doesn't explain the freeze. Next time the freeze occurs, please immediately open a Terminal and run: journalctl -b0 > journal.txt and attach the resulting text file here. ** Changed in: gnome-shell (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2058327 Title: Starting up Files app in external monitor freeze the entire monitor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/2058327/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs