Hi! I installed Extension:Collection on two wikis running MediaWiki 1.43 (appropedia.org and my test wiki mediawiki.solutions), and although I can create collections successfully, when I click on the "Preview with PediaPress" button to order a print, I get a long wait and finally an error ("There was an error while attempting to render your book"). I tracked the error down the source code and found that pediapress.com response contains "http-timed-out" and "http-bad-status" error messages, but the collections are made up of very normal public pages and all config options are on their default values. What could possibly be wrong?? Thanks for any help!