Thread:TheGreatEye/@comment-5230978-20130729193018/@comment-1967894-20130731162016

I see the reason now. Collapsible elements such as the Spoiler block template, and probably any Javascript-based code, does not work in articles Comments and Message Walls (such as this).

I assume you're using it in the Comments section in some article, right? I apologize, but there is nothing I can do here. It is an intrisic property of the MediaWiki software and as such I have no power to fix this. The only thing you can do is either use the Spoiler text template or use the Forums where you created the thread dedicated to Spoilers, since, despite seemingly having the same look as the Comments and Message Walls, it allows the usage of collapsible elements.