TileMill and Geojson; Datasource could not be loaded - json

Question

Im following this article to get a geojson file from an excel using Google Refine.
http://support.mapbox.com/kb/tilemill/converting-addresses-in-spreadsheets-to-custom-maps-in-tilemill
Now I've got the weird issue that I sometimes get the error message that the Datasource could not be loaded, while I'm using the exact same template everytime. The only thing different seems to be the data I'm loading.
Also if I compare the 2 geojson files (1 that is working and 1 that is not) I can see no difference.
Does anyone know what the problem could be? .. is it the use of spaces/breaks or whatever perhaps??
This one is working:
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"id": 25.019909,
"geometry": { "type": "Point", "coordinates": [121.365599, 25.019909] },
"properties":
{
"Users" : 1
}
},
{
"type": "Feature",
"id": 24.446706,
"geometry": { "type": "Point", "coordinates": [117.818197, 24.446706] },
"properties":
{
"Users" : 1
}
},
{
"type": "Feature",
"id": 25.100632,
"geometry": { "type": "Point", "coordinates": [117.03403, 25.100632] },
"properties":
{
"Users" : 1
}
},
{
"type": "Feature",
"id": 47.354348,
"geometry": { "type": "Point", "coordinates": [123.918186, 47.354348] },
"properties":
{
"Users" : 1
}
},
{
"type": "Feature",
"id": 30.199652,
"geometry": { "type": "Point", "coordinates": [115.03852, 30.199652] },
"properties":
{
"Users" : 3
}
},
...
...
...
}
]
}
While this one is giving me the error;
{
"type": "FeatureCollection",
"features": [ {
"type": "Feature",
"id": 25.019909,
"geometry": { "type": "Point", "coordinates": [121.365599, 25.019909] },
"properties":
{
"Users" : 1
}
},
{
"type": "Feature",
"id": 24.446706,
"geometry": { "type": "Point", "coordinates": [117.818197, 24.446706] },
"properties":
{
"Users" : 1
}
},
{
"type": "Feature",
"id": 25.100632,
"geometry": { "type": "Point", "coordinates": [117.03403, 25.100632] },
"properties":
{
"Users" : 1
}
},
...
...
...
}
]
}

Answer 1

You have an extra '}' in the second one. But, of course this may only look this way because of what you removed when adding the ..., so its impossible to say unless you post the whole thing that is not working.
Hint: find a text editor that highlights matching braces - most should do this if you tell the editor you are viewing javascript or json code.

Answer 2

I'm sorry.. it was something in the data after all :( .. tilemill is very strict in what it accepts and what not apparently..