Facing problem for editing document through Adobe Acrobat application

@Adobe, I am facing problem using the Adobe Acrobat application.I had a document which I had edited and had made some changes in it some weeks ago, but now on selecting the option of editing document, it is not allowing me to save the changes made in it by saying it is a 'read only document, changes will not be saved'.Please fix the issue as soon as possible, the problem is making me angry.