I just tried to install foregessentials-1.7.10-1.4.6.1360-server.jar to a departed 1.4.0 mod pack server and it crashed the server.
This is a fresh install of Departed with no additional mods installed. I'm just trying to get a permissions tool in place.
Removed the jar and the server started up normally
Is anyone available to assist with deciphering the error and possible identify the breakpoint?
I have attached the Forge logs with the error message in it.
fml-server-3.log
Thank you in advance.

Fastcraft is installed. Fastcraft has been known to cause issues thus, it is recommended to remove it unless you need it. Also, try updating Fastcraft as 1.21 is an old version.

I use fastcraft-1.23.jar and never had a crash myself. If that does not solve it might be another issue plus always try without fastcraft-1.23.jar just in case.