TypeError: Cannot read property 'lat' of undefined

[whyvez]

View details in Rollbar: https://rollbar.com/whyvez/bc-firemap/items/2/

TypeError: Cannot read property 'lat' of undefined
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in Object.project
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in Object.latLngToPoint
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in n.project
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in n._removeFromGridUnclustered
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in n._removeLayer
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in n.removeLayer
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in n._moveChild
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in n._childMarkerMoved
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in n.fire
  File "http://dev.bcfiremap.tesera.com.s3-website-us-east-1.amazonaws.com/static/js/main.32d83917.js", line 1, in n.setLatLng

[whyvez]

I think this is related to how they apply the key prop here: https://github.com/YUzhva/react-leaflet-markercluster/blob/master/src/react-leaflet-markercluster.js#L132

Your not supposed to use an iterator index for key.

Forked and troubleshooting but can't even build the project.