Internal Server Error after i try to rejoin alliance on alt (got alliance permissions on main)

Hello, i got the Internal Server Error after i send a request to join my alliance on alt ( on main i got permissions to accept requests and also asked different officers to accept the alt request and still get internal server errror). My alt name is NeamProst, my main is Horrorist, he's on K5 server and im trying to join XTC alliance but for some reason it cannot work. What should i do next?