Railworks America

On my new route I have created a free roam and simple standard scenario (with passing trains) successfully.
I tried to build a second scenario with passing trains. No matter what I did I couldn't get the timing right. Passing siding switches were created on curves built with easements. I moved the switches to no avail. I then deleted the scenario.
I went back to the first scenario, and it had been corrupted with the timetable screwed up (all times shown in red), and the paths not shown.
I then deleted this scenario, and started over. This time no red path was shown from the start to the target. Usually the program will set it's own path for the first train unless I change it. This time nothing.
Please, what have I done wrong, and how can I fix it?

Thanks all. I have the problem fixed.

All who?

I was thanking those in general who might be considering a fix to my problem. I found the fix by myself. I had a broken track which I had previously overlooked.
I was just trying to be considerate.