You notice that the system does not work after an upgrade, or that some JSP pages won't compile at all complaining that "The method runCheck(javax.servlet.ServletContext) is not applicable for the arguments (jakarta.servlet.ServletContext)" or similar messages.

This means that you are using a version of Tomcat and/or Java that is not supported by WombatDialer.

You need to use Java 8 (or 11) and Apache Tomcat 8 or 9 to make it work. If this is not supported by your OS, our suggestion is to run WombatDialer within a Docker container as explained here.

In particular, WombatDialer does not work with Jakarta Servlets (Tomcat 10), as they are a different interface from the one that has been historically used.

See also: Jakarta Servlet on Wikipedia