(Difficulty: easy) Test fixture Download a JNLP file, e.g. from here : http://docs.oracle.com/javase/tutorial/deployment/webstart/examples/webstart_ComponentArch_DynamicTreeDemo/src/dynamictree_webstart.jnlp Upload the JNLP file as a File resource somewhere, even in the frontpage "Download" the file from Moodle checking that the Content-Type Header is wrong e.g. if the JNLP file will be deployed in the frontpage you can use both the Browser Dev Tools ( F12 ) or an HTTP HEAD call via curl : # curl -I http://hostname/path/to/moodle/pluginfile.php/106/mod_resource/content/1/dynamictree_webstart.jnlp ... Content-Disposition: inline; filename="dynamictree_webstart.jnlp" ... Content-Type: text/html; charset=UTF-8 ... Test case #1 (Fixing the already uploaded files) Check that the same File resource now returns the correct MIME Type: # curl -I http://hostname/path/to/moodle/pluginfile.php/106/mod_resource/content/1/dynamictree_webstart.jnlp ... Content-Disposition: inline; filename="dynamictree_webstart.jnlp" ... Content-Type: application/x-java-jnlp-file ... Test case #2 (Checking new uploaded files) Upload again a JNLP file as a File resource somewhere, even in the frontpage. The file could be the same or something new found again around the network Check that the File resource returns the correct MIME Type: # curl -I http://hostname/path/to/moodle/pluginfile.php/<resid, must be different from the previous one being a new resource>/mod_resource/content/1/<filename>.jnlp ... Content-Disposition: inline; filename="<filename>.jnlp" ... Content-Type: application/x-java-jnlp-file ... Note: if you have Java correctly configured in your PC, a Java sample application will start few seconds after you'll click on that resource, out of your browser.