dokuwiki\Exception\FatalException: Declaration of renderer_plugin_dw2pdf::header($text, $level, $pos) must be compatible with Doku_Renderer_xhtml::header($text, $level, $pos, $returnonly = false)

An unforeseen error has occured. This is most likely a bug somewhere. It might be a problem in the dw2pdf plugin.

More info has been written to the DokuWiki error log.