This was in a post that got lost with all the server issues on Sunday.
I was running the Splitter scenario and encountered a red as I approached Victorville for the set out. Hitting 'tab' would not get me by the signal, so I went into the 2D map and started looking for approaching trains and found none. Then I started checking switches in Victorville yards and found one the was set opposed to my route. Once I had reset this switch I got a restricting signal and was able to move into the yard. I encountered this again at Ora Grande yard as I approached there with the empty hoppers. Again the 2D map showed me that there was a switch set opposed to the route I needed to take and once reset I got the restricting which allowed me to complete the scenario. There have been other scenarios that I would get reds which could not be explained and I am going to rerun them now knowing about the switches.