Minimum repro:
<mapframe width=500 height=500 latitude=-33.83 longitude=151 zoom=12>
{
"type": "ExternalData",
"service": "page",
"title": "Nonexistent.map"
}
</mapframe>Errors in JS console on page load:
Uncaught TypeError: Cannot set property 'dataGroup' of undefined
at ExternalGroup.<anonymous> (http://dev.wiki.local.wmftest.net:8080/w/extensions/Kartographer/modules/box/Map.js?ca93f:399:23)
at Function.each (http://dev.wiki.local.wmftest.net:8080/w/load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:384:23)
at Object.<anonymous> (http://dev.wiki.local.wmftest.net:8080/w/extensions/Kartographer/modules/box/Map.js?ca93f:389:7)
at Object.<anonymous> (http://dev.wiki.local.wmftest.net:8080/w/load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3305:33)
at fire (http://dev.wiki.local.wmftest.net:8080/w/load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3148:30)
at Object.fireWith [as resolveWith] (http://dev.wiki.local.wmftest.net:8080/w/load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3260:7)
at Object.<anonymous> (http://dev.wiki.local.wmftest.net:8080/w/load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3312:41)
at fire (http://dev.wiki.local.wmftest.net:8080/w/load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3148:30)
at Object.fireWith [as resolveWith] (http://dev.wiki.local.wmftest.net:8080/w/load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3260:7)
at Object.deferred.(anonymous function) [as resolve] (http://dev.wiki.local.wmftest.net:8080/w/load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3350:34)
(anonymous) @ Map.js?ca93f:399
each @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:384
(anonymous) @ Map.js?ca93f:389
(anonymous) @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3305
fire @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3148
fireWith @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3260
(anonymous) @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3312
fire @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3148
fireWith @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3260
deferred.(anonymous function) @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3350
(anonymous) @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3305
fire @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3148
fireWith @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3260
deferred.(anonymous function) @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3350
fire @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3148
fireWith @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3260
deferred.(anonymous function) @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3350
fire @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3148
fireWith @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3260
(anonymous) @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3312
fire @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3148
fireWith @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3260
(anonymous) @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3312
fire @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3148
fireWith @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:3260
done @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:9314
callback @ load.php?debug=true&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=0z62e7w:9718