URL rewriting doesn't work

After clicking on the "SADE" icon in the eXist-db dashboard, http://localhost:8080/exist/apps/sade/index.html opens and the following error occurs:

javax.servlet.ServletException: javax.servlet.ServletException: An error occurred while processing request to /exist/apps/sade/index.html: err:XPDY0002 variable '$project' is not set. [at line 27, column 40, source: /db/apps/sade/controller.xql]