Version 6.5 is full of bugs: (… normal sketchup model without any 3D geometry anymore … model in artlantis, packed with more geometries, which appear mysteriously …
Atl 4, normal file, correct! Unfortunately, this is a standard that I have been working on for a long time … I need to have sketchup 8 on my computer in order to export everything to artlantis 4, to work the whole file in artlantis 4, only to go to version 5 or now, try version 6 … I have duplicate work … I think abvent abandoned artlantis and focused on seeing only twinmotion, because it came full of improvements and news, since the artlantis had only 2 updates because the 3rd was to export just for the twinmotion … Abvent, you do not want to sell artlantis to another company more interested? 
Hello,
Sorry to hear you are having trouble with your SKP file and Artlantis 6.5.
Could you please, attach the SketchUp file and we will check it.
Best regards,