From UFStarfleet Wiki
These errors occur when the same field is duplicated in the document.
Would cause this error because the age field is in there twice. When this occurs, the wiki will display the most recent value (26) but also throw off an error message letting you know of a problem.
This category has only the following subcategory.
Pages in category "Pages using duplicate arguments in template calls"
The following 22 pages are in this category, out of 22 total.