My outlook is telling me that I can't move a message from inbox to another folder because it's been "changed", but I haven't changed the message at all. I only opened it. Anyone have a solution to this?
Try forwarding it to another account and then sending it back again (from the other account) to your in box.
Alternatively, open the email, copy its contents and paste them in to a new email. Sent that email to yourself and you'll hopefully have an email that you can then move wherever you want. This latter option should remove any glitch that has occurred in the original.