I am just not getting what is going on. I've done a complete search of the 1.5.5a site and can find no reference of where the boootstrap.min.css.map might be called or required. Yet, I get the 403. When I add the file, I get the Unexpected end of JSON input that I get on the 1.5.7c site.

Since neither is posting any warning or error, I'm hoping to find some correlation that can get me in the area of the problem. I am not making any sense of stack overflow or any other source trying to explain Unexpected end of JSON input and nothing specific to Zen Cart.

In short, I may need to know the answer in order to describe the problem.