Crystal server giving error HTTP Status 500

Hi,

I have installed the crystal server client tools 2013 on the machine where Crystal server 2011 is present. After this Crystal server has started giving error:

The error is:

HTTP Status 500

descriptionThe server encountered an internal error () that prevented it from fulfilling this request.

java.lang.NoClassDefFoundError:

What should I do to resolve it? Do I need to reinstall the server.

Regards,

Simran