Java Exception occured

[K0 M8 U8 2L8 0]

yo guys

As some know, i recently made my server. i started sending it to my friends from skype.
but the problem is that there are some people that actually get on and play, and some that get an error "Java exception occured"
Anyone know how to fix it? i'd be really glad if anyone helped.

;] thanks.

[elfranger243 0]

it's a java version issue, find out which java is used for the server/client, that's the version they need to play.

[bitmask 4]

Could you take proper image of the error?