If the "Preview" doesn't work... Rated 4 out of 5 stars

If the PREVIEW doesn't work (even after you've edited the install.rdf), you have to go to the bottom of this page, click on "Version Information", then on "View all versions" and get the LATEST version of CacheViewer (0.7b right now). The version on the main page is only 0.6.3 right now. Even in the latest version 0.7b you will have to edit manually the install.rdf file in the known manner.

This review is for a previous version of the add-on (0.6.3).