Error: Socket failed: Connection refused ltsp + update-rc.d errors

Question

I am installing a LTSP server, everything works, the pxe.linux.0 gets found, but the client gets stuck at this error:

Modprobe: module overlayfs not found in modules.dep
Error: socket failed: connection refused 
Exiting.
update-rc.d error cannot find a LSB script for lightdm
update-rc.d error no runlevel symlinks to modify, aborting!
Syncronising state for gdm3.service with sysvinit using update-rc.d...
Executing /usr/sbin/update-rc.d gdm3 defaults
Executing /usr/sbin/update-rc.d gdm3 disable
isserv warning current start runlevels empty of script 'gdm3' overrides SB defaults (2 3 4 5)
isserv warning current stop runlevels (0 1 2 3 4 5 6) of script 'gdm3' overrides LSB defaults (0 1 6)
update-rc.d error cannot find a LSB script for autofs

Attached is a picture of the errors.

Answer 1

Found out that nfs-common was failing. Was a directory problem in /etc/idmapd.conf. For ubuntu it is:

Pipefs-Directory = /var/lib/nfs/rpc_pipefs

And for debian it should be:

Pipefs-Directory = /run/rpc_pipefs

This solved the issues!