I am having this very same issue on a totally fresh GOG install. 4gb patch is applied (as far as I know, there is a backup of the exe created automatically), NAM installer reports no issues, game loads, but becomes "Not Responding" on city load. Cities load without NAM enabled.
EDIT: I suspect the 4gb patch isn't installing successfully despite the .bat command prompt saying it was? It appears that I'm able to load cities with the mod installed with the low memory option and the un-patched .EXE.
Further to this, I can load cities, mod enabled, with an allegedly patched .EXE, but only using the low memory NAM install option. The 4gb NAM install still crashes.
