Running 1.4.5 build 1334, the multiworld command does not work, spouting errors about a subclass not being in the inheritance tree and missing permissions even though I'm running directly from the server console (same goes as a logged in OP). Here's the error:

[20:39:53] [Server thread/WARN] [ForgeEssentials]: This should never be called! The subclass FECommandParserArgs should overwrite this.
[20:39:53] [Server thread/ERROR] [ForgeEssentials]: Error writing translation file.
[20:39:53] [Server thread/INFO]: You don't have permissions to use this command!

I have this trouble too. Who know how it fix?

So server write next:
https://gist.github.com/Electrodevice/3ee2ca04cbf78fcd3174f187f69e08c8

May be problem contein not in fe but in forge?
If You need other logs - say what some, I paste any.

Error exectly as in this issue
[§cOP§f] write /p group OPS allow * from console:
[12:30:14] [Server thread/WARN] [ForgeEssentials]: This should never be called! The subclass FECommandParserArgs should overwrite this.
[12:30:14] [Server thread/ERROR] [ForgeEssentials]: Error writing translation file.

and "You don't have permissions to use this command!" too.
/mw - the same result.
So I double it in #2202, but it similar problems, if You fix this - let me know.

Duplicate with #2202

Btw, @Electrodevice you error looks like a different error than this (based on the information you posted).

If you have more information that links #2202 with this one, please post your log in that issue.