Prevent text copying doesn't work with other PDF apps

@Rex Republic While Adobe Acrobat Pro allows you to apply restrictions, these are essentially "permissions flags" within the PDF file. Many third-party PDF viewers, like PDF Expert, are designed to read PDFs and display them, but they may not strictly enforce all of Adobe's permission settings, especially those regarding content extraction like copying text. This means that while they might respect the "no editing" flag (as that often involves structural changes to the document), they can often bypass the "no copying" restriction. 

If you are the owner of the PDF and have the permissions password (the one you set when you applied the restrictions), you can re-save the PDF and change the settings to allow copying again. Under the "Permissions" section, you'll see the option "Enable copying of text, images, and other content." Check this box to re-enable copying. You can adjust other permissions as needed (like printing). After saving, if you open this modified PDF in PDF Expert or any other viewer, the text should now be selectable and copyable because you've explicitly allowed that permission within the PDF's security settings.