Reason of pdf files is not opening :

• 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 programmes are updated on a regular basis. As a result, we can only recommend that you get the software through Adobe's official download page. Select the current OS system version and click the Download Now button while you're there.
• At startup, disable the Protected mode in Open Reader. For quick access, type Adobe into the search bar. In the top left corner, click the Edit button.Select Preferences from the Edit menu by scrolling down the Edit menu.A new window with several categories will open. By clicking on Security, you may improve your security.
• If the file is damaged, request that the sender transmit it again.-This isn't a typical issue, but it's conceivable that the PDF file wasn't created perfectly by the programme that created it. The PDF file may also include corrupt data at times.
• Repair software installation by reverting to a previous version for non-compliant PDFs

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