One big note is when durring modifing your rides always double click the red so the ride resets before you rebuild it, Also do that double reding reset while the game is paused. This should help prevent error trappers on redoing racing coasters and giga coasters with elevator lifts. I also recomend saving the game before modifing or building a ride. That is just in case you get an error trapper even when you use a trainer which incrases the chance of a error trapper.
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Chris Knight
If you have a problem with my grammer. Take a red marker and mark where the errors are on the screen.