Outlook error message when trying to move emails to folders

Solution 1:

When the status of an email changes i.e. from unread to read and you try to move it, you'll get this message UNTIL you mark/unmark a different item as read/unread; which seems to get Outlook's unruly attention to another item - then you can move the item you originally wanted to move. It's a bug and I doubt anyone's even going to pay attention to it.

Solution 2:

I had this issue with Outlook 2013, but not for all messages. This was occurring for messages that either had an empty subject line or messages that came from my HR department (for some reason). I found that I couldn't move them directly to the Inbox folder of a pst archive file, but it would let me move the messages to the Deleted Items folder of my pst archive file. Once in the Deleted Items folder, I was able to move them to the Inbox folder of my pst archive file. At some point outlook complained about having to repair the pst archive file. I did that once, and all was well.