Information

Full output of /ess version:

Server version: 1.12.2-R0.1-SNAPSHOT git-Spigot-642f6d2-57ab4cf (MC: 1.12.2)
EssentialsX version: 2.15.0.1
PermissionsEx version: 1.23.4
Vault version: 1.5.6-b49
EssentialsXProtect version: 2.15.0.1
EssentialsXChat version: 2.15.0.1
EssentialsXSpawn version: 2.15.0.1

Server log (upload logs/latest.log to Gist):
https://gist.github.com/KyaniteKingdom/b7df3e4a4e73098d592913e0743ae6db

EssentialsX config (upload plugins/Essentials/config.yml to Gist):
https://gist.github.com/KyaniteKingdom/179a497059b3a933f49312ae0fa51876

Details

I get a big error in console any time anyone places or uses a sign. I removed all other plugins and it still happens with only Essentials installed.

All I did to cause the above error was place a blank sign.

Thank you, that fixed it :)

Invalid string key in messages_en.properties:

[17:52:06] [Server thread/WARN]: Missing translation key "signFormatSuccess" in translation file en

Please check the messages_en.properties file.