There are a variety of reasons why a PDF file won't open
in Acrobat or Adobe Reader, including out-of-date software or a damaged PDF file.
this problem can also occur if the files were prepared with non-Adobe software or if you try to open some dubious PDF files. Additionally, the application itself, such as Reader or Acrobat, can be harmed.
Download and install the most recent version of Adobe Acrobat.
If you're using an old version of Adobe Acrobat, it might not be able to open all of your PDF files. Adobe's Acrobat and Reader programs are
updated on a regular basis.
As a result, we can only recommend that you get the software Adobe's (best in class) While you're there, choose the current OS system version and hit the Download Now button.