I'm having issues in that there seems to be an odd scaling or miss measuring factor happening when I export models and open them in Navisworks.
The Autocad models themselves are in mm but when I try to measure the same objects in Navisworks the dimension is shown in meters and has no relation to the actual distance in the model turning 725mm into 19.05m.
It doesn't seem to matter what I'm exporting my models as from AutoCAD I get this issue, is there an export or import setting I'm missing or a NW setting that I can't find?
Thats a scale factor of about 25.4 - I think there is some imperial conversion in there, maybe somebody updated the NWC cache file with their units set as inches?
I had the same problem but changed the "model unit" to feet even when I use mm in Revit and measure in mm in Navisworks.
Don't know why it works but it does and the measurements is correct in Navisworks.
You change "model unit" by right clicking on the model in the selection tree and chose Units and Transform.
Thanks thuzz - changing the units to something and than back again fixed it, no idea why but it seems to fix it.