Hello there!

I am here to report a quite large mod conflict / bug

Simply put if your server uses a proxy, the mod will refuse to allow any players to join because

[23:59:27] [Server thread/INFO]: com.mojang.authlib.GameProfile@5c6fbe4f[id=,name=ShawnTheCon_SL,properties={},legacy=false] (/[IP WAS HERE]) lost connection: This server requires you to install the Apugli mod (v2.5.0) to play.

Mind you the player has the mod to that version.
If you want to experience the bug yourself contact me on discord at @Moosheking

Fixed for 2.5.1. My config was set up incorrectly.