Execute Task (Export Web Map Task)

Unable to complete operation.
Error executing tool. Export Web Map Task : Failed to create layer from service at http://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer. Required 'mapOptions' property missing from web map JSON. Failed to execute (Export Web Map). Failed to execute (Export Web Map Task).

Web Map as JSON: (GPString)	{ "operationalLayers": [], "baseMap": { "baseMapLayers": [ { "id": "defaultBasemap", "opacity": 1, "visibility": true, "url": "http://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer" } ], "title": "Topographic" }, "exportOptions": { "dpi": 300, "outputSize": [ 1280, 1024 ] } }
Format: (GPString)
Layout Template: (GPString)
Options:
Output Spatial Reference:
Process Spatial Reference:
ReturnZ:	True False
ReturnM:	True False
Return True Curves:	True False
Return Feature Collection:	True False
Context:
Format: