This fix worked for me in Xubuntu 18.04 Bionic My laptop now successfully suspends after the inactivity period. Note that I had to restart in order for it to take effect:
https://askubuntu.com/a/851760/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1441460 Title: [xubuntu] Failing to sleep after inactivity - power manager error? To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xfce4-power-manager/+bug/1441460/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs