"This is not a valid Portable Document File (PDF)..." random error in Photoshop

[#1]

For the past couple of months I've been getting this error: "this is not a valid Portable Document File (PDF) document. It cannot be opened." error when I'm NOT trying to open anything.  I'd say it's happened maybe 10 times over the last couple of months and 9 of those times, it's happened when I'm waking the computer from sleep.  I can't seem to figure out any pattern to it.  It's like it's trying to open a file on it's own but it doesn't show in the recent list and I'm not seeing any action that could be doing this.

Any ideas?

{Thread renamed by moderator}

[#2]

For the past couple of months I've been getting this error: "this is not a valid Portable Document File (PDF) document. It cannot be opened." error when I'm NOT trying to open anything.  I'd say it's happened maybe 10 times over the last couple of months and 9 of those times, it's happened when I'm waking the computer from sleep.  I can't seem to figure out any pattern to it.  It's like it's trying to open a file on it's own but it doesn't show in the recent list and I'm not seeing any action that could be doing this.

Any ideas?

{Thread renamed by moderator}

[#3]

Hi there,

Sorry to hear about the PDF error, could you please try resetting the preferences of Photoshop and let us know if it helps?

https://helpx.adobe.com/photoshop/using/preferences.html

Regards,
Sahil

[#4]

Meant to answer you a LONG time ago and never did!  I've tried removing preferences and have cleared all my caches.  Even had an upgrade to photoshop in there.  Nothing seems to work.  Still happens randomly without anything specific happing to preclude it.

[#5]

I have the same issue. This error shows up when I wake my PC up from sleep. Happens randomly once a week.

[#6]

I have the exact same issue on my Mac as well.

[#7]

I have the same exact issue. 

[#8]

Also having this problem - notably I'm having it with a completely new install on a new machine. (i.e. not carrying over any settings whatsoever.)

I have a suspicion it is related to Photoshop not correctly handling the temporary files it makes, as it seems to only occur when photoshop is otherwise idle.

[#9]

I too have this issue. 

Photoshop in the background... with a single png file open (a tiny screenshot of a single layer)... working in other apps (Sketch, Slack, Chrome), and randomly get the "This is not a valid Portable Document File (PDF) document. It cannot be opened." alert, with an "OK" to dismiss.

It has happened thrice, weeks apart of each with no discernible pattern. 

Not a fan of apps trying to open things on their own... makes me security conscious/anxious. 

macOS Catalina 10.15.4
21.1.2 Release of Photoshop
3,8 GHz Quad-Core Intel i5
24GB 2400 MHz DDR4

[#10]

Same issue... awaiting an update or some response from adobe.

[#11]

Has happened to me several times as well. Just happened again. I was actually typing in Chrome, and Photoshop suddenly threw itself into the foreground with the "this is not a valid Portable Document File (PDF) document. It cannot be opened" message. Very suspicious that Photoshop seems to be trying to open a PDF on its own. Is this a security error? 

[#12]

Same red flag for me—security concern because this random error happens to me when Photoshop is NOT the active app. I haven't asked PS to do anything at all, certainly not asking it to open a PDF.

How about this: could it be related to clipboard handling? I know that at least on a Mac, the Adobe inter-app clipboard format is (or at least can be set to be) PDF. And this format conversion can happen as a background task, presumably. So one scenario could be that as I'm working away in another app, I've copied something that includes data that PS doesn't like for whatever reason, or thinks it should be able to convert to PDF but can't.

If assessing the contents of the clipboard IS a standard background task for PS, that would theoretically explain the startling behavior of PS jumping in front of my active app and declaring a phantom PDF to be invalid. If so, then perhaps Adobe should just supress the error until I try to paste into PS and not ... jump up in my face and freak me the heck out. 😉