Thread:SlyCooperFan1/@comment-26164607-20160512015535/@comment-1824272-20160512024101

Ahh... I see the issue. Look at Template:Infobox on the wiki, look at its source code. This section controls showing images:

If you look closely, the template is trying to add the  brackets and the 250px width by itself. Since you're using a tabber on the Panzer IV article for the image variable, the [[ and 250px are still going to attempt surrounding the tabber.

The code that the Infobox template is using is extremely outdated. You're better off creating a new PortableInfobox from scratch for different things like tank articles. See the source code for Template:Game for some code examples, and the source code at the top of Ace Combat 5: The Unsung War for its implementation.

On a side note, I had no idea World of Tanks included a tank livery from Girls und Panzer xD