I've done a little bit of investigating and worked it out that its something to do with the permission. My user ID is 1, so you can't add usergroups to it as it meant to have all the permission. I have another admin witch isn't one of the 1-3 user IDs, as i said before, you can't add uaergroups to. I then created a group with all the permission and activated it for that admin. The export and import now works for that admin!
So it must be something that the update messed up. Is there any way to restore all the permission for the main admins?