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[topic moved to Reader/Acrobat DC for Mobile forum]
The lock icon in the bottom bar indicates that the currently opened PDF document has some type of document restrictions.
The most common types of document restrictions are
- Commenting: Allowed / Not allowed
- Filling of form fields: Allowed / Not allowed
- Printing: Allowed / Not allowed
For example, to find out whether Commenting is allowed, tap the Comment button in the bottom bar of the Viewer screen.
If Commenting is not allowed, Acrobat Reader displays an alert like this.
If form filling is allowed, you will see field highlighting in light blue color.
In any case, you should be able to view a given PDF document.
Please let us know if you have additional questions. Thank you.
I can see the document but I can't type any letters. Thank you for your help.
Do you mean that you cannot enter any text into form fields?
(a) The PDF document does not allow form filling due to the document restriction/setting that is specified by the author of the document.
If you are not the author of the document, you will not be able to remove or change the restriction/setting in Acrobat Reader.
(b) The PDF document is encrypted because of document restrictions/settings. Acrobat Reader mobile products (for iOS, Android, Windows Phone) does not support any changes to encrypted documents. This is one of the limitations of Acrobat Reader mobile products.
Please use the desktop version of Acrobat Reader DC on a Windows or Mac computer to fill out the form. Sorry for the inconvenience.