Some blueprint functions didint migrate to another project

i tried migrating my main level which contains most of my game to another project to get rid of unused assets but I wasn’t able to play it bcz some blueprints had compile error. so first of all why did this happen also is this gonna happen when I cook and package my game too?

If the projects engine versions differ, then this could be a deprecation issue. Otherwise look at plugins, project settings. Make sure your new project is configured the same.