Certified Digital signature not allowing "Sign" click

When attempting to Certify (with visible signature) it will not allow the sign button to click at the end. The rectangle is drawn, the Sign with a Digital ID dialogue box pops up, the signature is selected, continue pressed, Sign As dialogue box appears, then permiteed actaions are selected, Review the Document, Appearance Integrity Report pops up, Warning comment selected, hit ok, box dissapears. Then the 'SIGN' button color is not longer faded. Yet, I am unable to to click the button. Nothing happens. I can click on all of the other buttons, but sign does no do anything.