Hello, I paid for Adobe Pro DC so I could open D.C. Documents on my iPad. when I open the Adobe app on my iPad and click the local documents is still says "This form requires Adobe acrobat DC for Mac or Windows". And yet a subscription to Acrobat Pro supposedly allows me to manipulate DC documents via iPad.
It seems that the PDF you are trying to open is an XFA form.
This particular type of PDF is not supported by Adobe Acrobat Reader mobile application.
You can open this PDF on the desktop version of Adobe Acrobat Reader DC/ Acrobat DC.