Will ARCGIS earth ever support .nmf files?
Unfortunately, there is no plan to support NMF file as it is ArcGIS Explorer data formats. Instead, my suggestion is to export it as a layer package. Refer to FAQ: Is it possible to open NMF files in ArcMap? And layer package support is in our pipeline. You are also welcomed to share the data as well as any details related to firstname.lastname@example.org, which will help us get a better clue of the user scenario.
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