User blog comment:C7X/What happened to Cantor's Attic?/@comment-44448911-20191205051709

Cantor came back from the grave and broke the site out of spite for modern set theorists calling Absolute Infinity impossible.

...but in all seriousness, it is likely that the software which hosted Cantor's Attic came into conflict with the MathJax neccesary to display the equations. That's an educated guess, only a MediaWiki whiz would be able to answer this for sure.