Why did Preview lock my PDF after I edited it??

It’s a bug in Apple’s Preview app. Many documents have passwords set but still allow the user to make changes or fill in the form. But Preview gets confused by that and demands the document’s original password, which people obviously don’t have.

I just had this happen (gotta love tax season). I right clicked the locked doc, and selected "open with" and opened it in Chrome and was able to see my edits. When I re-saved the PDF from Chrome it was fine.

Annoying but easy workaround, hope this helps!

Annoying bug, as I have to fill the same government form quite often. But here's my workaround: I downloaded the pdf, then opened it in PDFgear. Then in PDFgear I set my own password for the file and saved it. Now even preview recognises my password and I can use the same copy of the pdf over and over again (of course every time "save as" with a different name). Voilà. Bit of effort but at least I feel it was worth it.

The other small extra effort here is that PDFGear makes itself as a default app, but that's easy to change.

There earliest reference I find to this exact bug is from 2012. How could Apple ignore such a nasty bug for over a decade?!

Edit: I too had the problem with a (long) government form PDF file downloaded directly from a .gov website and another, also generated by the federal government but downloaded from an email I recieved. That one, actually had an owner password set and I knew what it was until I saved the file and that password no longer worked to unlock the file. Doh!

At some point, I thought something weird was going on and googled the problem, finding many reports but no real answers, except to never use Preview to edit a pdf file, not if you value your time and effort, and a lot of "experts" stating that Preview doesn't work that way, but yet it does, which is kind of the definition of a bug.

muffin21 wrote:

Thanks but it doesn’t even open it to me in chrome. It still asks for the password when I try to open it with a browser or any other way…

I've heard some people say they could still view the PDFs in Safari. I'm not sure about that.

I know that you can use Preview's File > Revert to > Browser all versions to find the last uncorrupted version of the PDF.

Same. Here’s my workaround:

I filled out the form, did a “save as” with a changed name to the m2 desktop, ‘printed’ that as a .pdf with a new name, opened that in preview and used the preview edit tools to make changes. Awkward, but better than losing it.

I’m surprised Apple has nothing to say about this basic use of a computer. I’d have thought they’d be able to figure it out.

Apple’s entire staff incapable of the solution?

I had the same problem, over and over again. I finally solved it: open with Edge (I had installed Edge on my MBA M3 for other reasons, much as I hate it). It opened, and I printed a pdf from there, as a file with the system dialog.

filipe124 wrote:

If they ever did "fix" it, it came back. It has been happening to me, using Sonoma 14.6, for the last weeks (the last time was yesterday).

I'll be happy to take a look at the file if you want to post a link to the PDF. So far, very, very few people have ever done that. For the few times that anyone did post a link, I've been able to confirm the bug exists (over a year ago) or confirm that the bug is fixed (more recently).

Re-download the file, duplicate it and try one of the PDF apps that Rickey_Sommer… suggested or my favorite, Skim. Monterey is now end of life so it won't be updated any more. Therefore, your only option is to find an alternative PDF file as suggested.

A workaround if you only have Preview is to print the unmodified PDF to another PDF, then edit that one! 🤦

filipe124 wrote:

It is unacceptable that this is still happening in 2024!

The last time I checked, Apple fixed this bug in Sonoma.

For anyone still struggling with this ( after preview locked an editable PDF I had been working on for 3 hours, the solution on this page worked for me. I have no idea what magic it performs, but don't care!

https://apple.stackexchange.com/questions/436596/preview-automatically-password-protects-pdf-when-saving2

Printing to another PDF worked, and it was no longer password locked. However, the ability to edit the new PDF was lost.

I also faced this issue today, and apparently I kept trying until I came across this page.

I tried opening the doc in chrome as suggested by few folks, didn't work for me.

In the end, I had to unprotect the document (Check the options under File menu option <password/edit permissions>) before trying to edit, and then I made the changes and saved it (I also copied this edited doc as a backup just incase it doesn't work) and then later I protected it back. This worked and can be tried out.

Happened to me on my tax returns docs that were sent to me from my accountant. I opened with the password the accountant gave me, added my signatures with Preview, then saved the PDF. I couldn't open it with my password to check it after that.

So I opened the original again, signed it, then changed BOTH passwords in permissions. The password used to open the doc AND the owners password. After doing that I I was able to reopen after saving. I first tried only re-entering the password used to open the PDF but that didnt work. I had to change both passwords.