Problems with loading activitys

I am trying to make some activity's for Crosby Valley but every time i try to load them up it keeps telling me
" failed to load shapes" and its a random set of shapes every time this only happens when loading an activity because when i load up explore mode every thing is fine and it loads up ok dos any one know why this is and how can i fix it
Many Thanks Dave

Dave,

Are you putting lots of AI and static stock in your activities? "Failed to load" usually means that your computer is struggling to cope with the load MSTS is putting on it. The fact that Free Roam works okay indicates that the route itself is okay.

Are you starting the free roam from the same starting location as the activity? If not, try that to make sure that there's not a problem with the route at that particular location.

Bob.