I’m not sure about that but it might be because you are using some editor-only blueprint classes (or components). I had a similar issue with my project where some actions would crash standalone play. Turned out I was using an arrow component in my character blueprint that was editor-only, so it wouldn’t be accepted as a valid class when trying to play in standalone or from a packaged build. I just had to replace this specific component with a normal arrow component.
Check if you are using some of these elements in your project and try to replace them with their non-editor counterparts.