Which one of them (the new 64-bit?) Any error message? And what kind of blueprint are you trying to export?
Yeah scenery blueprint there is one object and it has 169 000 polygons i really hope my problem is not because of that
That is exactly your prolem, 169 000 polygons in one object is way to much. You can have a maximum of 255 objects, and each can have ~30 000 vertices. This is a safe limit, you can have more but you will have a bigger risk of BPE failing to export. So the solution is to divide the object into several objects.
How do I divide them into different objects and if I do that can I move all of them together when placing them in game