Thread:Project:Support desk/Nuke mass deletion doesn't appear

The company that has created this wiki (http://www.ichscotlandwiki.org/index.php?title=Intangible_Cultural_Heritage_in_Scotland) has recently installed in it the extension Nuke by following these steps (https://www.mediawiki.org/wiki/Extension:Nuke). However, if the new "Mass delete" is clicked the result is a blank page (http://www.ichscotlandwiki.org/index.php?title=Special:Nuke). Does anyone have some suggestion for solving this? Thanks in advance for any reply.