Steps to reproduce:

• Create a page such as:

<maplink latitude="43.739" longitude="43.528" zoom="7" show="a,b,c,d"/>

• Refresh the page, click on the link.
• The map may not appear at all
• Seeing in the console::

VM2434:1 Uncaught SyntaxError: Unexpected token u in JSON at position 0

Although this sounds like a corner case at first, I noticed it on Russian Wikivoyage... The maplink in the corner is broken. This makes it a very high priority bug :/