Can't Open pdf document, file is incorrectly decoded
Hello.
I have a PDF doc which somenbody sent me its link the other day, I downloaded the file but I whenever I open the doc is shows me this 
I spent some time googling this issue but unfortunately the solutions were all too complicated for me to follow. Apperantly this happened because the uploader didn't zip the doc into a winrar, he can't send it again.
Here is the solution if somebody would like to see it:
https://helpx.adobe.com/acrobat/kb/pdf-error-1015-11001-update.html
Online 'pdf repair' sites do not work.
If anybody could help me I would be grateful
