Jail Door Nasty Error Message

I was placing object in my server with the console on my other monitor and when I placed a jail door and salvaged it by accident I noticed a giant error message. The error message appeared not after I placed the jail door but when I salvaged it!
I have no idea if it is even related to the jail door if a rocket plugin!

Plugins

Workshop Mods

There was no error messages well launching the server.