Possible causes:

1. JS files are not extracted when using default Zip utility on Windows (especially for 64 bits machines)

Diagnosis: Check tomcat/webapps/contour/js to see if jx.js file is there

Solution: Download 7zip and use 7zip to unzip Contour release file

2. Client Browser Cache

Solution: Clear cache and refresh (or Ctrl-Shift-R)

3. Tomcat working directory cache (for Contour update)

Solution:

a. Stop Tomcat.

b. Delete {Tomcat}/work/Catalina/localhost/contour

c. Restart Tomcat