What kind of problem would lead to the error?

the error is Internal Servlet Error, the description is " Cannot create bean of class". Please tell me the possible cause, thanks a lot!
[151 byte] By [e_moon77] at [2007-9-26 4:42:50]
# 1
Ok, this maybe useful for the people who have the same problem: http://forum.java.sun.com/thread.jsp?forum=45&thread=162685
e_moon77 at 2007-6-29 18:06:26 > top of Java-index,Enterprise & Remote Computing,Enterprise Technologies...