Why have my PDF files stopped opening since yesterday?

PDF files stopped opening since yesterday:

• There are a variety of reasons why a PDF file won't open in Acrobat or Adobe Reader, including out-of-date software or a damaged PDF file.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 programmes are updated on a regular basis.
• At startup, disable the Protected mode.
• 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. Furthermore, if the file was transmitted through USB or website, it is possible that it did not transfer completely to the stick or to the website. Adobe Acrobat or Reader, or the resources on which they rely, may be harmed, rendering them unable to perform their functions properly. Repairing the installation is the best option here.
• You can either utilise the control panel to fix the application or open it and pick Help > Repair programme installation, which is the easier option.

Read More: Why can't I copy text from a PDF file?