Changing The Document: Not Allowed

Hi, I just came across this forum because I was having the same problem. I eventually figured out a solution that worked for me, so I thought I would post it here if it might help someone. I have Adobe XI Pro and was not able to edit a document that had no security settings made by Adobe 7, I kept getting the message that it was signed. I went to Tools>Forms>Edit Form, and I got an error saying the document was signed, but it also asked me if I wanted to save a copy, so I did. Then I was able to edit the copy just fine. I had tried the "save as" option before that and it did not work, so it seems that 'saving a copy' and 'save as' are not the same. There may be another way to save a copy, but that's the solution I came across.