Hey there, the reason this is happening is because you have a plot that at the same time is both the parent and the child of another plot. That causes a circular connection that breaks the page.

In order to fix that, open your articles and categories manager, filter from the top left to see only the plot type articles (optional) and then go through the list checking each plot to find out the parental relationships.

We will also investigate on our end to fix the issue so this doesn't happen in the first place