How to make a PDF file read only if it's already opened by another user

[anezrap72970224]

We are using a pdf file for a database that is updated frequenly. How can I block a user from accessing it (or only allowing it to be opened in read only mode) if another user already has it open so that their changes aren't lost?

[try67 · Accepted solution]

This is something that needs to be done at the file and folder permissions level. It's not something you can do in the PDF file itself or the application.