Broken links on website, motif page

[Dboingue]

Two of the motif named on that page, have their links being clicked result in an internal server error page notice.

listudy.org/en/motif/zugzwang
listudy.org/en/motif/overloading

While I don't think this is a browser issue, as the other links do lead to page with diagram and expected content, I can share that I am using Edge updated (as of this writing), on windows 10, also updated.