Exit from Driver.
Go to Surveyor
Go to layers, and merge both the Session and Route layers together. This should ensure that the train shows.
I use the route layer strictly for buildings, tracks, industries, and other related to the world-stuff.
I have found that when I do anything in Surveyor, I do not save a session. All sessions are saved when I edit a session later on.
When saving, choose Save or press CTRL+S.
Choose do not save Session.
When you get ready to run your trains, close Surveyor, and remember to do the save thing as before.
Choose Sessions, and edit in there.
Here in the Session Editing, which look the same as Route editing so don't be tempted to move a tree or adjust the height of anything, you can place your trains, consists, and edit rules.
Save the Session, and create the session under any name you want.
Sometimes, if you need to edit a portal, you do have to choose the route layer in the session. This is normal. Sometimes too you may be prompted to save the route while in the session. This is normal and do so as requested.
John
This will keep the route separate.