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Paul2020
Inspiring
April 14, 2026
Answered

26.001.21431 Update MSP does not work

  • April 14, 2026
  • 3 replies
  • 395 views

The latest update - 26.001.21431 - does not work for Adobe Acrobat Reader.

26.001.21431 Planned update, Apr 14, 2026 — Acrobat-Acrobat Reader Release Notes

I usually push the MUI Reader update without issue, but when I try to run this MSP I get the following error:

 

“This patch package could not be opened. Contact the application vender to verify that this is a valid Windows Installer patch package.”

 

Is there something wrong with the latest patch? The ones before it worked fine. The Acrobat Pro patch for today also worked fine.

EDIT - Looks like the one from April 10th also doesn’t work. The last patch I used without issue was AcroRdrDCx64Upd2600121367_MUI.msp

Correct answer Paul2020

Oddly that error comes up without the /qn switch for MSIEXEC, but with it the update works. I still don’t know why it’s giving an error in Intune, but I’ll have to figure that out on my own. 

3 replies

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defaultz79d7l3v30va
Participant
April 20, 2026

Do you know which tool was blocking it?

Packasso
Packasso
Participant
April 17, 2026

Cause identified: Security solution corrupted the download

We were able to narrow down the problem:
The update (AcrobatDCx64Upd2600121431.msp) itself is not actually faulty.

In our case, the cause was as follows:
In our environment, either the antivirus or other mechanisms within our security architecture apparently interfered with the download.
As a result, the MSP file was modified or corrupted, which subsequently led to installation errors similar to those described.

Solution:
After downloading the file again via an unchanged/unfiltered path, the update installed without any issues.

P
Paul2020Author
Inspiring
April 17, 2026

Not in our case, I tried redownloading and the same issue occurred. As I mentioned below it seems to happen if you omit the quiet mode switches (/qn). Not sure why that would make the difference, but it did. 

P
Paul2020AuthorCorrect answer
Inspiring
April 14, 2026

Oddly that error comes up without the /qn switch for MSIEXEC, but with it the update works. I still don’t know why it’s giving an error in Intune, but I’ll have to figure that out on my own. 

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