Hi, I have created a stateless session servlet as is in the link

Hi,
I have created a stateless session servlet as is in the link forum.appian.com/.../Custom_Servlet_Plug-ins.html. When i access this servlet with another session open i am able to view the tasklist. But if i access this servlet without another open session, an popup appears asking for user credentials, when i give them it throws a 500 internal server error. Please find the attached error log and attached java class and Servlet configuration file.

Error.log

OriginalPostID-143395

OriginalPostID-143395