it doesn't crash, it hangs, with xorg stuck at 100% cpu, and no there's nothing in /var/crash
it does seem to be a new issue, tho as i said, i don't watch all that much really. i'll attach dmesg and Xorg.0.log, however note their dates: $ ls -lt dmesg Xorg.0.log -rw-r--r-- 1 root root 47383 Feb 6 11:34 Xorg.0.log -rw-r----- 1 root adm 31 Oct 15 2016 dmesg perhaps you wanted this: sudo apt-get install xdiagnose tho now apport-collect asks for my password, which is peculiar because i'm already logged in as g, and it acts as if i type my password wrong. i tried twice, carefully entering my password when it asks: $ apport-collect 1744429 Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged. ==== AUTHENTICATING FOR com.ubuntu.apport.root-info === Authentication is required to collect system information for this problem report Multiple identities can be used for authentication: 1. g 2. g 3. g Choose identity to authenticate as (1-3): 1 Password: polkit-agent-helper-1: error response to PolicyKit daemon: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: No session for cookie ==== AUTHENTICATION FAILED === Error executing command as another user: Not authorized This incident has been reported. Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged. $ ** Attachment added: "Xorg.0.log" https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1744429/+attachment/5050145/+files/Xorg.0.log -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1744429 Title: [Dell OptiPlex 755] PC freezes while playing vlc or youtube To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1744429/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp