Type of bug

Compatibility issue, Error in console

/ess version output

Server version: 1.17-R0.1-SNAPSHOT 3147-Spigot-9472b09-d7ef1e9 (MC: 1.17)
[15:12:44] [Server thread/INFO]: Brand version: CraftBukkit
[15:12:44] [Server thread/INFO]: EssentialsX version: 2.19.0-dev+248-1179caa
[15:12:44] [Server thread/INFO]: Economy Layer: None
[15:12:44] [Server thread/INFO]: Vault is not installed. Chat and permissions may not work.
[15:12:44] [Server thread/INFO]: You are running an unsupported server version!
[15:12:44] [Server thread/INFO]: Fetching version information...
[15:12:44] [Craft Scheduler Thread - 2/INFO]: You're running the latest EssentialsX dev build!

Server startup log

https://paste.gg/p/anonymous/9699942740874423909b207479350a93

EssentialsX config files

https://paste.gg/p/anonymous/62bf9377de444b2583cc51405de636e4

Error log (if applicable)

https://paste.gg/p/anonymous/e30a91ca5b40493ab060d5b81bb99910

Bug description

From what I understand this bug occors because of the interaction of ACF and the array call on line 36 of the AlternativeCommandsHandler class.

Steps to reproduce

1. Make a plugin using ACF and register the command
2. Download EssentialsX
3. Exception should be thrown and a stack trace should be in console when the plugin enables

Expected behaviour

Essentials should either ignore commands built in ACF or support them like any other command built using the bukkit api.

Actual behaviour

The command helper class will be null and cause null pointers for the rest of the runtime

Fixed in #4508. Download the latest dev build for a version that includes this fix.