The problem is, I am not even getting an error message when trying to install. I simply cannot select to install on the extension manager. See here: http://imgur.com/a/FZtCr I am using the war I got here: http://download.forge.ow2.org/xwiki/xwiki-enterprise-web-8.4.2.war And I am at a loss to explain why this won't do at all. Especially since installing pegdown manually did not seem to help, since pegdown has a dependency on parboiled and that seems to have been ignored, or maybe I did something wrong there.