can't use wireless redstone

[thegamer]

Whenever I try to craft a wireless transmitter or receiver on a Tekkit server I get disconnected and shown this error message: null.pointerexeption . This has happened to me on two separate servers and I haven't been able to reconnect. This problem does not appear to crash the server.

[RalphRoberts]

Maybe they are banned? I would try reinstalling the launcher just to be safe, and see if they are banned on those servers.

(I have no idea what that error means, these are just suggestions)