If you can see document information (filename, recent activity, user avatar) in Live PDF for Android, but cannot open the PDF for viewing, check the following:
Is data disabled or does your device have a weak network signal?
With data disabled (airplane mode) or without a network signal, you will be unable to download and view PDFs.
Do you have an app for viewing PDFs, and is it working properly?
You can test this by navigating to any PDF on the web in your device browser, then observing how your device responds. If you need to add a PDF-viewing app, several are available for free download (including Adobe Reader) at the Play Store.
If you can view your PDF but it does not display properly, try using a different PDF-viewing app. You may need to change file association on your device to allow the new PDF-viewing app to be used for displaying PDFs. The precise pathway for changing this may vary by device. Searching the web for "android change pdf association" will provide a number of helpful instructions.