How to view loading errors in the game?

I have a route that I have corrected so that it produces no warnings or errors while loading it in route viewer. There is however one error while loading the route and train in the game. Is there a way in the game to find out what error that is?

I'm using OpenBVE 1.7.157.1280 and route viewer 1.5.2.0. on Windows 10 Pro (1909).

Sure, there is. OpenBVE produces quite a detailed log, which is cleared when a new driving session is started. So, start up the route and train combination in the game and then check this path:

C:/Users/YourUserName/AppData/Roaming/openBVE/Settings/log.txt