Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Thunderbird - cannot open pdf files prior to sending an email. Worked for years no problem - what has happened and how to fix?

  • 3 cavab
  • 0 have this problem
  • 4 views
  • Last reply by Toad-Hall

more options

In Thunderbird 107.7.1 on my MacBook Pro with M1 chip - When attaching a pdf to an email getting ready to be sent I am not able to open it and check if the pdf file is in good shape. I use Adobe Acrobat Pro as my preferred pdf reader and this is associated in control panel. I always check pdf's prior to sending to make sure it is correct. As soon as I click on the pdf attachment in the ready to send email I get the following "File name - Cannot be opened because an unknown error occurred. Try saving to disk first and then opening the file." However, I am able to open pdf's with Acrobat Pro that are attached to emails that I receive without a problem. I have used Thunderbird for many years and this needs to be solved so I can do my business properly. Please advise as to how to get this corrected. Thank you. Bud

In Thunderbird 107.7.1 on my MacBook Pro with M1 chip - When attaching a pdf to an email getting ready to be sent I am not able to open it and check if the pdf file is in good shape. I use Adobe Acrobat Pro as my preferred pdf reader and this is associated in control panel. I always check pdf's prior to sending to make sure it is correct. As soon as I click on the pdf attachment in the ready to send email I get the following "File name - Cannot be opened because an unknown error occurred. Try saving to disk first and then opening the file." However, I am able to open pdf's with Acrobat Pro that are attached to emails that I receive without a problem. I have used Thunderbird for many years and this needs to be solved so I can do my business properly. Please advise as to how to get this corrected. Thank you. Bud

All Replies (3)

more options

have you changed the setting in Thunderbird to open PDF files internally? I am guessing not.

more options

Matt - not all of us are Top 10 Contributor Moderators so your answer to my question, although I'm sure well intended, does not assist me in any way. Could you please send me more complete instructions on how to change the settings in Thunderbird to open my PDF files internally so you do not have to "guess not". Sending me the HOW to solve my issue would be much more productive for all concerned as I see others have the same issue and I suppose would keep your Top 10 ranking. A win-win for everyone. Thank you for your assistance. Regards, Bud

more options

re : Could you please send me more complete instructions on how to change the settings in Thunderbird to open my PDF files

Menu icon > Settings > General scroll to 'Files & Attachments' section

Contents Type: 'Portable Document Format (PDF) Check the 'Action': eg: Adobe Acrobat Pro

It might say: 'Preview in Thunderbird' (This opens the pdf in a tab in Thunderbird) or 'Ask me' or 'Save File' or another option, make sure it has selected 'Adobe Acrobat Pro' or 'Adobe Acrobat DC' or whatever program you choose to use.

I'm running Windows 10 OS (not MAC) and all works ok for me. Sorry I cannot test on a MAC.