Can't really play the game since it's not for Windows but I had the same problem with vertex colour materials, must be some bug in Unreal not including that in packaged project. I gave up on vertex painting after few hours and just used regular textures instead :D
Viewing post in Feed me Seymoure! jam comments
Another mistake by me. I made it for android but didnt see the option to tag it when uploading. Strange thing is everything else is vertex painted too and works fine. Only the trees and the water have this problem. Well i guess iam going to look into the problem so i can do a better job at the next jam. Wanted to save some time with the vertex paint since i started on saturday and wanted to the assets myself. Really could have used the extra day to polish it more. Well was my first try.