Convert Pdf file back to original format

[Judith5E0C]

Today I opened an email on my phone and when I clicked on the file, a box popped up telling me to rather open with this version for a better experience. So I clicked on it and now it has changed the whole format? I dont know which version it was  I just clicked and now I need to know how to convert my Pdf file back to original format please?

[Kris5EF8]

Thanks very much. I did download a file and it seems to be working fine
now

[Judith5E0C]

Can somebody help me with this query please????

[Test Screen Name]

Sorry you haven't given us anything to go on. What app were you using before? Which ones now? Screen shots might help. Oh, and what sort of phone?

[Judith5E0C]

Adobe Acrobat is installed on my Android