A corrupted or damaged PDF file is the cause of your PDF file not opening. This type of inaccuracy can be caused by a variety of factors. For example, the file may have been damaged as a result of a malware attack, or it could be due to a file error.

But the real danger begins when one of your critical files becomes corrupted. There are many data recovery tools available that can assist you in getting the most out of your file with the least amount of damage.

Opening your PDF file in a different reader is another approach to see if it's working or not. If you can open the file with another reader, then the problem might be in your Acrobat reader. It may be outdated or needs reinstallation.