Hey [USER=“1805733”]The Gugaru[/USER] ,
I got your message, but rather reply here so others can see in case they have the same issue. Those are the Structs created for MRT. How did you migrate MRT to your 4.19 project? Did you click on folder ‘MRT’ and Migrate the entire folder? From the error it looks like you are simply missing those files in your project.
Can you try to migrate the entire folder to your game? Let me know if that fixes the issue.
Thanks!