Skins not showing on server

[Marshenn]

Hello there. I made a server for some of my friends and I to play on. The problem is that our skins don't show and I have no clue how to fix it. I've already changed it to online mode in the server.properties. I dont know if it has something to do with the fact that the modpack is 1.6.4. Any solution would help, thanks.

[coolcolinc]

Im having the same problem on all servers any idea?

 

[JaariAtmc]

Mojang took all Pre-UUID skinservers offline. Any modpack before 1.7.10 (and some 1.7.10 ones) will no longer show your skin on servers.