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Not all PDF files display correctly using "Preview in Firefox"

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  • 1 has this problem
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  • Last reply by PeteJG

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A pdf from the following link doesn't display using the "preview in Firefox" setting. I see a blank page and the file turns up in my downloads folder. If I change the setting to use Acrobat DC it displays in acrobat ok. All pdf files from the same site behave the same. https://myvolunteering.nationaltrust.org.uk/Stourhead/file/Spring-2018.pdf

However a pdf from the following link works ok with the "preview in Firefox" setting. Again, all pdf files from this site behave the same. https://probus-gillingham-dorset.org.uk/Uploads/sendFile/366

I'm using firefox 59.0(64 bit). I have automatic updates set so firefox is automatically up-to-date. This used to work ok, so far as I can tell it started failing around December 2017.

Any thoughts please?

A pdf from the following link doesn't display using the "preview in Firefox" setting. I see a blank page and the file turns up in my downloads folder. If I change the setting to use Acrobat DC it displays in acrobat ok. All pdf files from the same site behave the same. https://myvolunteering.nationaltrust.org.uk/Stourhead/file/Spring-2018.pdf However a pdf from the following link works ok with the "preview in Firefox" setting. Again, all pdf files from this site behave the same. https://probus-gillingham-dorset.org.uk/Uploads/sendFile/366 I'm using firefox 59.0(64 bit). I have automatic updates set so firefox is automatically up-to-date. This used to work ok, so far as I can tell it started failing around December 2017. Any thoughts please?

All Replies (5)

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Hi, seems an issue that only affects users who have turned off cleartype font rendering within their windows settings. so a workaround for the moment would either be to turn cleartype back on or disabling hardware acceleration in Firefox: Firefox's performance settings https://support.mozilla.org/en-US/kb/performance-settings

Please check to see if this makes a difference.

If fails to make changes after restarting Firefox or enable cleartype please : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

Reinstall with Current Release Firefox 59.0.1 with a Full Version Installer

Please let us know if this solved your issue or if need further assistance.

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Hi PeteJG, it's a server configuration issue. This URL:

https://myvolunteering.nationaltrust.org.uk/Stourhead/file/Spring-2018.pdf

sends Firefox an unusual content-type header:

  • Content-Type: application/unknown
  • content-disposition: filename="Spring-2018.pdf"

They certainly could send application/pdf if they want browsers to handle the file normally, so I don't know why they are doing that. Or to put that another way, I don't know whether they are intentionally bypassing normal PDF handling or whether someone made a mistake somewhere.

Modified by jscher2000 - Support Volunteer

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Thanks for your replies guys.

Pkshadow: I did all that (cleartype was already turned on) but unfortunately it's still the same. I'm pretty sure it did once work, but am beginning to doubt my certainty. I thought it worked around December time but I've got an ageing version of linux mint with Firefox 56 installed last October and it fails on there. I have an old ios9 ipad with firefox & it works on there. Of course IE/edge works by calling Acrobat. Not to worry though I'll follow up jscher2000's suggestion.

jscher2000: I'll feed that back to the National Trust, thanks. BTW, did you persuade Firefox to show you the header or did you need a network trace?

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Hi PeteJG, the Browser Console can show network requests and responses, so that's where I found the headers. (If it's a page load in the same tab, the Network Monitor is easier/better.)

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OK Got it, thanks very much.