Why does this PPTX need repaired?

Ian Peterson 55 Reputation points
2025-06-04T19:01:06.01+00:00

I have this PPTX my company's software generates and when opening it in powerpoint it prompts that it requires a repair. I compared the repaired version to the broken version with the Open XML Productivity tool and manually went through a lot of the internals but they are identical from what I can tell. Hopefully somebody here can shed some light on whet the repair step is actually changing so I can correct my document generation. Looks like I can't attach PPTX files so I have links to where they can be downloaded.

Broken Doc:
****/out_prime.pptx
Repaired Doc:
**out_repaired.pptx

Microsoft 365 and Office | Open Specifications
Microsoft 365 and Office | Open Specifications

Technical documents for protocols, computer languages, standards support, and data portability. The goal with Open Specifications is to help developers open new opportunities to interoperate with Windows, SQL, Office, and SharePoint.

Answer accepted by question author
Tom Jebo 2,451 Reputation points Microsoft Employee Moderator
2025-06-12T01:19:16.6033333+00:00

Hi Ian Peterson,

Sorry this took so long but it's often like finding a needle in a haystack. I did find one thing that seemed to make PowerPoint happy in the end.

In slide1.xml and presentation.xml you had <custDataLst> blocks. They were both in what appeared to be valid locations per our schema definitions.

In presentation.xml on line 12, you had this: 

  <p:custDataLst/>

and in slide1.xml on line 194, you had this: 

    <p:custDataLst>
      <p:custData r:id="rId1"/>
      <p:custData r:id="rId2"/>
    </p:custDataLst>

Although these looked to be in valid placement, when PowerPoint reported the error and then repaired, removing these was among the many changes it made. In isolation, I removed them and it made PowerPoint happy with everything else left alone from the original.

So while I don't have a full explanation as to why PowerPoint wanted them removed, I suspect that it considered them conflicting with the non-visual shape properties occurrence of custDataLst in slidelayout12.xml.

I hope this helps,

Best regards,
Tom Jebo
Microsoft Open Specifications Support

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  1. Anonymous
    2025-06-05T06:35:10.42+00:00

    Hi @Ian Peterson  

    Thank you for reaching out to the Microsoft Q&A Forum. 

    Please understand that our forum is a public platform, and we will modify your question to cover your organization domain name in the description. Please notice to hide these personal or organization information next time you post error or some information to protect personal data. 

    I understand that you're facing an issue where, despite comparing the repaired and original PPTX files using the Open XML Productivity Tool and finding no visible differences, PowerPoint still prompts for repair.  

    Unfortunately, I’m unable to access the file you shared due to permission restriction. Please provide a screenshot of the repair prompt or error message that appears when you open the file? That would help us better understand what's going on. 

    I'm looking forward to your update. 

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