We apologize for the inconvenience this may have caused.
Would you please provide more details about the problem so that we can help you?
What happens when you try to open a PDF document in Acrobat Reader for iOS?
Does Acrobat Reader disappear and take you back to the iOS home screen? When you re-launch Acrobat Reader, do you see the following dialog?
Does the same problem happen to all of your PDF documents or a particular PDF document?
Would you be willing to share your PDF document and crash logs with us (Adobe)?
We should be able to provide the instructions on how to fix the problem once we determine the root cause.
Thank you for your help.