Sorry to dredge up the past, but yesterday I restored a version 1.16 wiki from backup and my users can not upload PDFs anymore. The error returned is: Fatal error: Call to a member function toHtml() on a non-object in /<my wiki dir>/ImagePage.php on line 457 I suspect a thumbnailing issue, as the PDF files do actually upload. And this only occurs with PDFs. I've scheduled an upgrade on Saturday to 1.22, but I have to fix this before hand. I've already changed all perms on /images to 777 to rule that out. I'm at a loss what to do next. Any help would be much appreciated. Thanks Bill