An outdated browser may be the issue, in which case you may need to update your browser to resolve the issue. You can usually run a regular software update, but other times you may be required to update manually through the menu. Not all browsers update automatically, and it could be that yours needs a manual update. Solution: This is one of the most common problems that can prevent you from being able to read a PDF. Here are the three main reasons why you may have a problem reading a PDF on Mac and what you can do to solve the problem. This is due to a variety of reasons, but luckily this problem is usually quite an easy one to solve in just a matter of minutes. Many people experience problems when trying to open or read PDFs on Mac.
Part 2: Troubleshooting on Opening and Reading PDFs in macOS