Nested X server (Xnest) problems

The bit that causes issues for most users is the nested X server. Custard uses Xnest to provide this functionality.

/tmp/.X9-lock file exists

The most common problem is Xnest leaving behind a lock file, even though the window has been closed. This is sometimes caused by not logging out of the Gnome session properly before closing the Xnest window.

Custard's main interface has a tool, under Troubleshooting, to remove the stale lock files.

Custard always starts Xnest as display :9 with its output on display :0

Custard tries to get permission from your X server to output on display :0. If this fails, you must manually execute 'xhost +' (sans quotes) to allow Custard permission to display the nested X server on your currently running display (assumed to be :0).