The last two PDFs I've saved (vXI 11.0.03, OSX ML) with my standard security settings--no changes allowed, printing and everything else allowed, no password required to open or download--have somehow become locked. The file appears with a padlock icon instead of its cover page facsimile. Users of Mac browsers and tablet/phone devices are either unable to download the files without a password or unable to open the file if download completes. Interestingly, users of Windows browsers don't experience download or open issues.
On checking, I found that security is set to conditions other than what I actually set when saving the files. If it had happened once, I'd say "user error" and be done with it. Happening twice makes that very unlikely. Is something going on with security settings in Acrobat XI?
Clarification: Unintended (wrong) setting is "Require a password to open the document" box checked. Is there a reason that selecting the file attachment encryption radio button automatically selects this checkbox? If the PDF in question has no attachments, would this matter? What is considered an "attachment" in this context? Thanks.
A PDF file may have attachments which are other files (PDF or other file types) that are embedded in PDF and can be opened separately. "Encrypt only file attachments" requires open password, and you cannot set permissions password for this enryption type. When you encrypt only attachments, you can open the main PDF without password, but to open any attachment you need to provide the password.