Sorry for late reply.Looks like you have added password using designer. Please use adobe acrobat to open that form. Then go to File and open properties. Select Security Tab and if you know the password you can change the settings to allow you commenting and other things.I recommend choose " Commenti...

How did you enabled or extended features ?I suppose you used adobe Acrobat. If yes then that was the time to allow user to do other things as we'll.Choose commenting, filling and printing.If you designed in Livecycle designer, please make sure you set the target version latest to use the most latest...