We have identified a bug in the previous release where we do not show some parts of some PDF files. I am really sorry that this is happening to you. If you would be willing to share a sample file, I can confirm that this problem will be fixed in the upcoming release. Please email it to me at firstname.lastname@example.org.
We just released Acrobat Reader for iOS version 15.4 on January 23, 2016.
This release includes the fix for the particular defect that you have encountered.
Would you please give it a try and let us know if it works for you?
If you have trouble updating Acrobat Reader from the Apple App Store, please take a look at the following page for tips: http://adobe.com/go/updatehelp