Arobat reader Mobile Android will not fill and sign a prepared form

I have prepared a form in Acrobat and distributed it but when it is opened in adobe Acrobat Reader on Android with Fill & Sign, it says, "Restricted document is not allowed because it is a read only file. But on a computer the same document. I need forms to be filled and signed on both Android and IOS. The fill and sign Adobe app apears to work for unprepared forms only.