When you create a field for article relations, it is possible to select the same category as the content type you're using (which is fantastic! ^_^). Although, this allows for a cyclic relation issue.

The current article you're editing can be related to itself. Wouldn't this cause an infinite loop as you try to get an object in itself in itself in itself etc.

Say you have content type A in category Z and then you create a related article field and tell it to look at category Z. Then you assign this field to content type A. Now when making a content type A article, you can take the article you are currently on and relate it to itself. This would cause the issue on render.

My suggestion for a fix is to filter the results so the article you are currently editing cannot be related to itself.