How to preserve file size for large prints when using light effects?

Can you send us a screenshot or an example ofnthe style your tryinn to create?

Plus a shot of the error message,as so we can best assist you?

I have no idea what you are talking about. You need to be much more specific and tell us about actual resolutions and dimensions. That said, yes, some filters have built-in hard limitations because they use GPU acceleration or simply because they are old as moldy bread and Adobe never updated them to modern times, but quite likely there's a million ways to re-create whatever effect you want manually using other techniques.

Mylenium