I wasn’t able to really read the errors from the screen shots above, but I’ve just been through the same learning path this week so take a look at the project file here and let me know if this helps fix your error?
This is the completed AddVehicles action for the POST method (For some reason the images get truncated in the forum view? but if you right click you can download them to see them in full)
Thanks so much for sharing the project with me! I will take a look and see where are my mistakes are and I will try to reproduce again with the help of your project and the tutorial. Hopefully this time I wont receive any weird errors again haha.. I am also trying to understand how this whole thing works so it really helps that you shared your project with me. Thank you once again! I will respond here again if it is successful this time.