java.lang.NoClassDefFoundError

Hi Experts,

I unable to start Integration Builder(SXMB_IFR),

when I try to enter into Tcode: SXMB_IFR, I got following error....

500 Internal Server Error

Exception

An internal error occurred. Contact you XI administrator

java.lang.NoClassDefFoundError

Please help me, how to come out from this error.

Regards,

Chandrasekhar