We created manuals on Adobe Pro that has fillable edit fields for notes and it's password protected. Everything seemed to be working just fine on PC and Mobile Devices until this past weekend when we noticed that on mobile device the fillable edit fields are locked. The security settings are set for users to still edit the editable fields.
When password protection is applied to a PDF document, the PDF document will be encrypted.
Acrobat Reader mobile products (for iOS, Android, Windows Phone) have the known limitation where changes cannot be saved to encrypted PDF documents. Therefore, users are not able to make any changes (e.g. filling out forms or adding comments/annotations) to encrypted PDF documents.
As you already know, there is no such limitation in the desktop version of Adobe Reader or Acrobat.
Sorry for the inconvenience.
Inconvenience - this is more like a major flaw in the mobile versions of the software.
Is it known if there are any plans in place to resolve this issue with future app versions?