In what way don't they work? If they are faulty, then you will need to right-click them in Content Manager and use View Errors and Warnings to find out what's up.
1. Oper the asset in Explorer.
2. Open the Config file.
3. Find the line "Train Build [space] "build number" (e.g. 3.6, 2.0)
4. Change whatever the build is to 3.7.
5. Save the Config file.
6. Commit the asset.
Im even lost here. Both of the UP and BNSF GEVO's work just fine in TS12 SP1. Not sure what error you are getting but make sure you have the correct engine sound for your version as well as the correct engine spec and other dependencies.
And also please more detail helps everyone try to help you much easier. The asset kuid, name, etc etc goes a long way other than " es44 is faulty"