Any time I try to add the poem
tag, the page crashes and I get the message " Class 'Html' not found in /var/lib/mediawiki/extensions/Poem/Poem.class.php on line 56" in the apache error.log.
Topic on Extension talk:Poem
In which wikisource are you working? Can you give me the name of a page where such error pops out? And please - have you an user name somewhere?