Hi, I've gotten that same error message occasionally and usually it means that I have been trying to export something that has too much texture or rasters too large (like the terrain imagery) for the exporter memory to process. (I 'm working on an old XP machine with only 4GB of memory) Try exporting just one or two buildings to see if the whole process is working for you. Scott
Should not take days .. That seems something for Esri support ..
Maybe check the polycount ..
[[ Tip : Test your workflows always just on maybe 1 building or 1 street segment. Then, if all works grow the amount of data you transport at a time.. ]]