OpenEMM cannot send email

[project]

Hi,
i've got an error message when i clicked on the 'normal button' at the page of new mailing. Here's the error message:

An error occurred

Cause: javax.servlet.ServletException: org.apache.jasper.JasperException: javax.servlet.ServletException: javax.servlet.jsp.JspException: ServletException in 'mailing/mailing-view-base.jsp': org.apache.jasper.JasperException: Unable to load class for JSP

I've tried to find out solutions but still cant fix it, so could anyone help me? thanks a lot.

[maschoff]

Please specify the version of OpenEMM you use.