When building my new track, and testing it so far online i got this error :
http://users.pandora.be/mumhra/error/error.jpeg
Here on this site i found out this was the problem : "This happens in tracks with a large number of high-vertex objects. Remove objects with a high vertex count. For example, trucks used as props and/or animated bins. A work around is to reduce view distance in hardware options"
Now there aren't that many visible boxes or objects in it yet. But there are lot's of invisible walls. Does those error also count for those invisible ones ? Because if they do, i'm in big trouble