Is there any way to fix the error from a PDF file?

Urgent- I'm trying to open a PDF document and I get an error message that says possible damage has occurred because it may have been an e-mailed document that was not properly decoded before e-mailing. I just downloaded the latest version 8.1.1 version of Adobe and still get the same error message. Any one else been successful at retrieving one of these

Hi 

please tell me which file you have a problem?

Daniil Prysiazhnyi  I don't think this designer has any issue with designcontest, it is a personal issue they are trying to get help with

You can modify the way PDF is generated or produced if you manage or administrate software that generated PDFs automatically. For this, you must take care of the fact that no irrelevant bytes should appear before %PDF at head of PDF file.

If it don't work the document is lost for good. 

Perhaps  this authoritative source will also help you.

https://forums.adobe...6978758#6978758

Well, I can't claim my solution would be 100% correct in all the cases, but that's what I do when it occurs. Things like that happen to me really, mostly always when I receive a document via email, because don't know, maybe gmail hates them. So, what I do is fixing the very PDF manually with the editor - have no confidence with Acrobat, but I use this one https://990-pf.pdffiller.com/ Furthermore, I have no clue solid enough to explain how it actually works, but I just upload this file and do some minor edits (change the font to another and back or something) and everything works after all