it's likely a kernel bug if the whole system freezes, so maybe try newer/older kernels:
http://kernel.ubuntu.com/~kernel-ppa/mainline/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1752145 Title: system freeze after full screen video viewing with Xorg on ultrawide monitor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1752145/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
