So, you are sure your driveline and the Start is on the track (like on pictures - 1st is correct, 2 nd is wrong)...
Try couple things:
- open the Timing Gates window and move the Start couple meters (move manually or enter it's new position in digits). I also think it's not the best idea to place the Start banner at 0 meters - I usually make the driveline longer before it's original beginning and set it like 10-20 meters. (Anyway, there's a method if you want to drive the closed circuit over and over - place Start, Stop and Finish at 0 meters
)
- I believe you don't have panel length like 25 or more meters - in that case car can fall into the space too
- Is your track driveable? Collisions are not enough
- make the copy of the track, leave at least 3 control points at the beginning - delete the rest (if you tend to leave less than 3 - btb will crash!) If this works - delete the first 3 control points from original track - both should be merged perfectly (maybe just minimal correction would be needed). You will loose couple terrain's poygons (first row), but it shall not be a problem to build them again.
- the emergency way could be - delete the driveline, centerline and everything (pacenotes too...) and attach it again.
- build some flat, short wall and place it 1-2 cm over track in the place where you start - make it driveable and collidable - test - can your car move from the start and drive over the track?
- if anything from above works - I'm sorry... (out of ideas) - Find the latest working version of you track and build again. Test often (before saving), make backups etc. Bad things happen sometime with btb...
Important:
to switch beetwen btb and rbr, you have to launch rbr in windowed mode (look in rbr's RichardBurnsRally.ini file - there must be
Fullscreen = false
to allow the windowed mode) - in other case btb will possibly crash when you switch back.
The situation like yours used to happen to me when I was creating very short and straight track for testing new objects. (long panel, two control points etc.)