Some PDF files may contain restrictions preventing actions such as printing, editing, copying, etc.
To review the permissions that have been listed on the file, click the "File" > "Properties" > "Security" button.
You can add a password to a PDF document to limit access and restrict certain features, such as printing, copying, and editing. There are two kinds of passwords that could be applied to a PDF file: Open Password and Permission Password. When you set the Open Password, anyone who tries to open the PDF file must type in the password that you specified. When you set a Permission Password, anyone who wants to change the restrictions must type the Permission Password. Please note that if a PDF is secured with both types of passwords, it can be opened with either password.
To remove the password from a PDF file by PDFelement, you must enter the password first. After opening the PDF file, click the "Protect" > "Set Password" button, type the permission password if requested, then uncheck all the options in the new dialog box to remove the password.