EDIT: I’m an idiot. It’s /Core/ not /CoreUProject/… Ignore me, I just misread the location.
That file is missing in Version 4.25.3 for me. I ran a verify and the file was still not restored, continues to not exist.
Is it possible for another user to upload a copy of that which I could download? Or do forums block header uploads, even in archives?
Otherwise, I may just install an older version of the engine and see if I can duplicate the header from there.