I just wrote the line above: "kernel.sched_compat_yield=1" directly to /etc/sysctl, and the app (vmware-workstation) never showed the message again (screen shot at the top of this page). If I just said yes to the message, the app would create the file "30-vmware-player" in /etc/sysctl.d/ but I would still get the message after running vmware-workstation after rebooting (maybe because the name of t