it wont let me onto any sever

hello it Toby here

i reporting to that since 22/6/16 i have not been aloud on any servers.
i want this to stop happening and i want to know what to about it.
Describe what you thought should happen here

*What actually happened was i came onto minecraft went onto cubecraft server adn thn i started to play egg wars and then it siad sorry but a problem occured and it happened when i went on a differnt server as well
Describe what happened here