|The most common issues with a PDF are as follows:|
Password protection blocks opening the PDF.
PDF was created with a non-Adobe program and doesn't comply with industry standards.
File is damaged.
Sometimes a PDF file becomes damaged or contains corrupt data. If you downloaded the PDF from the Web or received it in an email, download the PDF again or ask the sender to resend it. Copy the file directly to your hard drive, rather than a thumb (portable) or network drive.
Open the new copy directly from your hard drive.
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