# Cannot highlight certain pdf documents
**URL:** https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423
**Category:** DEVONthink
**Tags:** devonthink3
**Created:** [March 22, 2020, 8:01pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423 "2020-03-22T20:01:33Z")
**Posts on this page:** 14
**Page:** 4
### Author:  [@aedwards](https://discourse.devontechnologies.com/u/aedwards)
#### Post date: [February 23, 2023, 9:14am UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/61 "2023-02-23T09:14:43Z")
This is a workaround to a bug in Apple’s PDF kit. After a document is OCR’d we will attempt to transfer any annotations or attributes from the original document to the OCR’d document. For certain documents this is not possible as a PDF kit bug would cause the text layer in the PDF to be corrupted.
---
### Author:  [@chreliot](https://discourse.devontechnologies.com/u/chreliot)
#### Post date: [June 9, 2025, 7:46pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/62 "2025-06-09T19:46:34Z")
Having struggled for a while with a PDF I couldn’t highlight in DTPro 4(b3), I just want to document here what worked for me in the end. The file was not encrypted, had all permissions enabled, and had a text layer—kind PDF+Text. It turned out it was locked.
- I opened the PDF in MacOS Preview app from within DTPro (⌘⇧O).
- I attempted to highlight a passage using Preview’s highlighting tool.
- An error message popped up saying the file was locked, but offering the option to unlock it. I accepted unlocking it.
- The PDF can now be highlighted in DTPro, and the highlights show up in the Document \> Annotations inspector.
---
### Author:  [@BLUEFROG](https://discourse.devontechnologies.com/u/BLUEFROG)
#### Post date: [June 9, 2025, 7:59pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/63 "2025-06-09T19:59:09Z")
Did it actually say it was locked or did it save it couldn’t be saved but you could save a copy?
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### Author:  [@chreliot](https://discourse.devontechnologies.com/u/chreliot)
#### Post date: [June 9, 2025, 8:01pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/64 "2025-06-09T20:01:56Z")
It definitely said it was locked and couldn’t be saved but that it could save a copy. Apparently DTPro then automatically worked with that copy.
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### Author:  [@BLUEFROG](https://discourse.devontechnologies.com/u/BLUEFROG)
#### Post date: [June 9, 2025, 8:02pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/65 "2025-06-09T20:02:42Z")
- Was it in the Global Inbox?
- Where did you save the copy to?
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### Author:  [@chreliot](https://discourse.devontechnologies.com/u/chreliot)
#### Post date: [June 9, 2025, 8:06pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/66 "2025-06-09T20:06:06Z")
No, it was not in a Global Inbox, but rather in a regular database. (It went by quickly, I’m afraid, as I didn’t realize I was watching the solution, but) I believe I did not save anywhere but simply hit the Okay button. I think it over-saved the document in DTPro.
I can try to re-download the file and reproduce it more slowly if that’s useful.
---
### Author:  [@BLUEFROG](https://discourse.devontechnologies.com/u/BLUEFROG)
#### Post date: [June 9, 2025, 8:09pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/67 "2025-06-09T20:09:04Z")
No worries!
If it’s publicly accessible, you can just post the link.
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### Author:  [@chreliot](https://discourse.devontechnologies.com/u/chreliot)
#### Post date: [June 9, 2025, 8:45pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/68 "2025-06-09T20:45:20Z")
I reproduced it. Here is the text from the dialogue box in Apple Preview:
> The file “Deriving-example.pdf”
> is locked.
> If you want to make changes to this
> document, click Unlock. To keep the file
> unchanged and work with a copy, click
> Duplicate.
>
> - Unlock
> - Duplicate
> - Cancel
---
### Author:  [@tamara6](https://discourse.devontechnologies.com/u/tamara6)
#### Post date: [June 13, 2025, 6:39pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/69 "2025-06-13T18:39:39Z")
Rats! I thought this would help with my issue, but it doesn’t. I have a PDF that I have marked up before in DT, but now is claiming to be locked. But I can open it in preview (through DT - command shift O) and can highlight things and save the file, go back to DT and it shows those new highlights, but the file still has the little locked symbol, and I can definitely not highlight it in DT.
I’m sure it is corrupted, or formatted oddly, because it is a dissertation from ProQuest and I’ve already had two of them that were corrupted. Still, if it works in preview, it seems like it should work in DT.
---
### Author:  [@chrillek](https://discourse.devontechnologies.com/u/chrillek)
#### Post date: [June 13, 2025, 6:44pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/70 "2025-06-13T18:44:17Z")
Willy don’t you just unlock it?
---
### Author:  [@BLUEFROG](https://discourse.devontechnologies.com/u/BLUEFROG)
#### Post date: [June 13, 2025, 6:50pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/71 "2025-06-13T18:50:17Z")
Do you have a [support ticket](https://helpdesk.devontechnologies.com) open on this?
---
### Author:  [@tamara6](https://discourse.devontechnologies.com/u/tamara6)
#### Post date: [June 13, 2025, 7:06pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/72 "2025-06-13T19:06:55Z")
I don’t know how to unlock it (or do I? does it involve the hidden settings?)
I don’t have a support ticket for two reasons: (a) I’m on vacation and am only “working” about one hour a week - that would be this hour that I’m in right now 🙂 and (b) it isn’t that big a deal - I’m sure it is the pdf’s fault, not DT’s, and I’m fine with going to preview to highlight it.
---
### Author:  [@BLUEFROG](https://discourse.devontechnologies.com/u/BLUEFROG)
#### Post date: [June 13, 2025, 7:08pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/73 "2025-06-13T19:08:04Z")
Enjoy your vacation! 😃
---
### Author:  [@chrillek](https://discourse.devontechnologies.com/u/chrillek)
#### Post date: [June 13, 2025, 7:26pm UTC](https://discourse.devontechnologies.com/t/cannot-highlight-certain-pdf-documents/54423/74 "2025-06-13T19:26:19Z")
> [@tamara6](#):
>
> I don’t know how to unlock it
Did you check the integrated help and user manual for that?
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