PDF files display illegible and hover/preview with illegible characters

What I’m trying to do

Up until today, PDF documents embedded in notes previewed exactly as they appear when viewed in the Adobe PDF Reader. Today, the PDF previews are illegible with misc. characters.

This may be a bug but I decided to try posting to Help first to see if anyone else is experiencing this.

I’m running Obsidian v1.3.5 on Windows 10 Pro OS build 19045.3086

Things I have tried

I have searched Help and the forum as well as searching Google for Obsidian PDF preview display illegible characters and I have found nothing about what I am experiencing.

I have re-opened this Vault as well as restarted Obsidian.

I have checked for Updates to both Obsidian and Plugins and applied.

I pasted a snippet of what I am currently seeing in a sample document. This is what I am seeing for all PDF documents in all notes both when they are set to display with the ! in front of the embed as well as when I hold Ctrl and hover over the embedded link to the pdf files.

How does the PDF look if you view it here: PDF.js viewer?


I’d also try in the Sandbox, using Restricted mode in your vault, etc… if you haven’t yet. The troubleshooting steps are here.

Thanks for the response and for something to try.

I’ve never used this PDF.js viewer but I gave that a try and I see the same illegible content.

Here is a snip of that attempt. Does that help?

PDF.js (that link) is the “engine” Obsidian uses for viewing PDFs, so if it doesn’t work there, I don’t think there’s much the Obsidian team can do about it.

I’ve seen this before in PDFs with CJK (Chinese, Japanese, and Korean). It’s an encoding issue with whatever made the initial PDF. Text will be fine in the app that made the PDF, but it may not be viewable in other apps and produce results like this.

1 Like

Thanks for reminding me to try both Sandbox and to try Turn Off Community Plugins and restart.

In both troubleshooting approaches I am seeing the same illegible content in PDF.

Here is a snip of the same PDF file in Sandbox with a ! link placed in a new note.

and a snip of that PDF in one of my Vaults with Community Plugins Turned Off and Obsidian restarted.

Yeah, it’s good you tried in the Sandbox, but that won’t help us here unfortunately. See my above post.

I wondered about that. Most of the PDFs I work with are English but have a Company Chop (stamp) that is Chinese or Korean.

Here is the Chop from the sample PDF

What caught me off guard was that the hundreds of PDFs that I’ve added over the past 6 months have viewed and previewed perfectly for over 6-months and then seemingly out of the blue this illegible viewing began today. I checked various “vintages” of PDF documents assuming that something in the encoding had changed with new documents added today but all PDF documents are impacted including those that have a last Created and Modified Date/Time of December 2022.

I make use of this specific Vault 7-days a week (60-80 hours per week) so I can pinpoint that this began today.

Do you have any ideas how I might research what could possibly have changed within the last 8-hours so that I can attempt to rollback some local dependency that PDF.js may have?

The new PDF viewer came with version 1.3.0 and I think that was released publicly with v1.3.4. Is it possible that Obsidian updated in the background and you haven’t restarted in a while? An update can download in the background but won’t be applied until a restart of Obsidian.

That’s the only thing I can think of, as nothing has changed or been released in the last few days. See the full Changelog for details: Obsidian Changelog - Obsidian

If it’s not sensitive, you could post a link to one of the PDFs here (or DM me the PDF or link) and we could take a look.

1 Like

I have resolved this issue for the moment by not running Adobe Acrobat and Obsidian at the same time. Everyday I concurrently run both Obsidian and Adobe Acrobat and have not experienced the illegible characters issue.

For whatever reason, today running both Obsidian and Adobe Acrobat caused PDF rendering in Obsidian to manifest this issue.

To clarify further for anyone else who may stumble onto this thread, I closed out of Adobe Acrobat and I restarted Obsidian at which time the issue stopped.

I didn’t think that there were any underlying dependencies or ties between Obsidian, PDF.js, and Adobe Acrobat but after this occurrence I believe that there may be some either intentional or unintentional connections between some or all of the three.

Thanks @ariehen for your patience, tips, and troubleshooting help!

Now that is weird. And with Acrobat closed, is the PDF rendered fine in PDF.js viewer ? I wonder if Acrobat has hooks (an extension) into the main browser you use. :thinking:

Strange interaction indeed.

1 Like

Yep. With Acrobat closed, the PDF renders correctly in PDF.js viewer (in Chrome) and in Obsidian.

Prior to 6/29/2023 (Friday), I don’t recall any rendering issues when Acrobat and Obsidian were both open concurrently.

I wonder if temporary hooks are created when I right-click on a PDF file in the Obsidian left pane and select Open in Native Application…

Two scenarios/test cases I did not try:

  • disabling Acrobat as the default PDF viewer in Chrome or
  • testing rendering in PDF.js viewer in Firefox or IE/Edge.

Again, thank you @ariehen for your patience and troubleshooting guidance here on the forums.

1 Like

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.