Can not print mixed size documents using version 26.001.21771

Hi @Amal Jaiswal,

Thank you for your reply.

Here are the results of my investigations:

Environment

• Adobe Acrobat Reader 64-bit 26.001.21771
• Windows 11 25H2
• Multiple workstations affected
• Canon printers (Canon Generic Plus PCL6 driver)
• Microsoft Print to PDF also tested

Troubleshooting already performed

• Cleared Acrobat Reader cache.
• Fully uninstalled and reinstalled Acrobat Reader.
• Tested on multiple Windows 11 workstations.
• Tested with different printers.
• Tested with Microsoft Print to PDF.
• Tested with Foxit Reader using the same PDF files.
• Reviewed PDF properties:
  • PDF Version 1.6
  • Generated with iText Core 7.2.6
  • Documents contain mixed page sizes.

Results

❌ Printing fails when "Choose paper source by PDF page size" is enabled.

✅ Printing works when "Choose paper source by PDF page size" is disabled.

✅ The same documents print correctly with Foxit Reader.

❌ The issue also occurs when printing to Microsoft Print to PDF, which seems to rule out a printer driver issue.

Windows update testing

I initially suspected a recent Windows update because the issue appeared shortly after Windows updates were installed.

To verify this, I:

• Uninstalled KB5101684 (preview update).
• Tested again.
• Uninstalled KB5101650 (security update).
• Tested again.

The mixed-size printing issue remained unchanged.

Therefore, I no longer believe this issue is directly caused by Windows updates.

"Print as Image" testing

I tested the workaround you suggested:

Print > Advanced > Print as Image

Unfortunately, the document still fails to print, even when printing to Microsoft Print to PDF.

This workaround does not resolve the issue in my environment.

About the rollback test

Unfortunately, I am using the free version of Adobe Acrobat Reader and do not have access to previous installers through Adobe support channels.

As a result, I am currently unable to roll back to version 26.001.21677, so I cannot confirm whether the issue was introduced specifically between versions 26.001.21677 and 26.001.21771.

Conclusion

At this point, the evidence suggests a regression related to 26.001.21771:

• Multiple workstations affected.
• Same behavior across systems.
• Reinstallation does not help.
• Microsoft Print to PDF fails.
• Foxit Reader works correctly.
• Disabling "Choose paper source by PDF page size" works around the issue.

Please let me know if Adobe has already identified this issue internally or if there are any logs or diagnostic tools I can provide to help investigate.

Thank you.

This worked for me. 

Disable Protected Mode

Go to Menu > Preferences or press Ctrl + K.Select Security (Enhanced) from the left sidebar.Uncheck the box labeled "Enable Protected Mode at startup" and click OK.Close Adobe Acrobat completely.Open Task Manager and end all Adobe related tasks to make sure everything is fully stopped.Reopen Adobe Acrobat for the changes to take effect.

Since the issue started right after updating to 26.001.21771 and it happens with multiple printers, it sounds more like an Adobe Reader issue than a printer problem.

You should try printing the same PDF with an older version of Reader, if possible, to confirm. You can also try Print as Image (under Advanced in the print dialog) to see if that works. If it does, it may be a bug introduced in the latest update, and Adobe may need to address it in a future patch.

We're experiencing the same issue with the latest 64-bit version of Adobe Reader (26.001.21771). We were able to temporarily resolve the problem by switching to the 32-bit version of Adobe Reader and disabling the following security settings:

• Enable Protected Mode at startup
• Enable Enhanced Security

After completely closing and relaunching Adobe Reader, the options worked as expected.

P.S. I don't remember whether we also ended up using the "Print Ad Image" option.

- Jorge Raigoza
The Computer Support People

Hello, I believe I have the same issue. A legal department using a terminal server is now having issues printing their mixed-size documents following the most recent Adobe Acrobat update (26.001.21771). The previous version installed was 26.001.21691.

Same here. Workstations that have received the latest update are seeing the same issue when selecting the “Choose paper source by PDF paper size” option. Print as Image does not fix it. I have tried uninstalling/reinstalling Adobe Acrobat with no success yet. Very frustrating. 

I had a coworker who was using 26.001.21677 try to print my document and he was able to successfully print the document. I am not able to roll my version of adobe back. I am using adobe acrobat on a windows pc. I do not pay for Acrobat Pro. I have verified that “Choose paper source by PDF paper size” is selected, also “Print as Image” also fails.

​Hi @srice1553 ,

Hope you are doing well and thanks for reaching out, and sorry for the trouble, especially since this only started after updating and you have already ruled out a specific printer as the cause by testing multiple ones.

A couple of quick questions to help narrow this down:

• Are you using Acrobat Pro or Acrobat Reader, and Windows or macOS?

• If you have the option to roll back to 26.001.21677 (the version you were on before), does printing mixed sizes work again there? That would confirm this is tied to the .21771 update specifically, rather than something else that changed around the same time.

A few things worth trying in the meantime:

1. Please check the help page on printing mixed page sizes in Acrobat, which covers the specific settings this feature depends on (the "Choose paper source by PDF page size" checkbox in the printer's Adobe PDF Settings, not just the Acrobat print dialog), and it is worth confirming those are still set correctly after the update, since updates can sometimes reset printer-level settings.

2. Try "Print as Image" under Advanced print settings in the Print dialog. This bypasses some of the print pipeline that has caused mixed-size regressions before, so it can work as a stopgap even if it is not a permanent fix.

3. Since 26.001.21771 was only released on August 1, 2026, check Adobe's Known and fixed issues page over the next few days, since this is exactly the kind of update that introduces regression, which tends to get listed there once confirmed, along with a fix timeline.

Let me know what you find with the rollback test and whether "Print as Image" works as a stopgap, which will help confirm whether this is the update itself or something specific to your setup.

~Amal