I noticed that when we turn on the whitelist and a player not added to the list attempts to connect to the server console receive this error:

[15:28:57 INFO]: Disconnecting com.mojang.authlib.GameProfile@13d18540[id=e76f9ae4-5295-3286-85d2-8e16341cd0fb,name=NeonDmn,properties={textures=[com.mojang.authlib.properties.Property@5c64dbe7]},legacy=false] (/37.47.107.145:38792): ?7?l[?b?lL?3?lP?7?l] ?cPermissions data could not be loaded. Please contact an administrator.

Will look into it. I've noticed the same thing.

[19:14:12 INFO]: UUID of player Lucko is 7edb3771-6862-318f-9565-df5b318cf080
[19:14:12 INFO]: Disconnecting com.mojang.authlib.GameProfile@f1851bf[id=7edb3771-6862-318f-9565-df5b318cf080,name=Lucko,properties={},legacy=false] (/127.0.0.1:64855): You are not whitelisted on this server!
[19:14:12 INFO]: com.mojang.authlib.GameProfile@f1851bf[id=7edb3771-6862-318f-9565-df5b318cf080,name=Lucko,properties={},legacy=false] (/127.0.0.1:64855) lost connection: You are not whitelisted on this server!

Huh, weird. I can't reproduce now...

I've tried to reproduce in a number of different circumstances and have been unable to get it to break. Any ideas?

Closing for now, since as far as I can tell, this isn't an issue anymore. Feel free to reopen if you're still experiencing the issue.

Should be fixed :)