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pippaschoeman's avatar
pippaschoeman
Copper Contributor
Sep 10, 2025

PDF not Opening from Mail

I have just bought a new MacBook Air and upgraded to Microsoft 365.  I have some important PDF files to open which needs a password to open them.  When I click on the file an error message comes up s...
microsoft 365
Kidd_Ip's avatar
Kidd_Ip
MVP
Sep 14, 2025

How about this:

 

  1. Use Adobe Acrobat Reader

 

  1. Save the PDF to Your Desktop First

Instead of clicking the PDF in Mail:

  • Right-click the attachment > Save As > save to Desktop.
  • Open it from there using Preview or Acrobat Reader.
  1. Check for Updates

Make sure your Mac and Microsoft 365 apps are fully updated:

  • Go to System Settings > General > Software Update.
  • Open App Store, search for Microsoft apps, and update them.
  1. Try Opening with Preview (manually)
  • Right-click the saved PDF > Open With > Preview.
  • If Preview doesn’t prompt for a password, try Acrobat Reader instead.
  1.  Disable “Enable native OS mode” in Acrobat

Some users with M1/M2 Macs found that disabling this setting helped:

  • Open Acrobat > Preferences > General.
  • Uncheck “Enable native OS mode for optimal performance”.

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