PPTX export produces PowerPoint repair dialog and removes unreadable content

What version of Codex CLI is running?

codex-cli 0.117.0

What subscription do you have?

Not specified

Which model were you using?

Not specified

What platform is your computer?

macOS

What issue are you seeing?

A generated .pptx file opens in Microsoft PowerPoint with a repair flow, which indicates the exported presentation contains invalid or unreadable content.

Affected file:

generated_presentation_ascii.pptx

When opening the file, PowerPoint shows:

PowerPoint found a problem with content in generated_presentation_ascii.pptx.
PowerPoint can attempt to repair the presentation.

If you trust the source of this presentation, click Repair.

After clicking Repair, PowerPoint shows:

PowerPoint couldn't read some content in generated_presentation_ascii - Repaired and removed it.

Please check your presentation to see if the rest of it looks ok.

So the file is not cleanly readable by PowerPoint and some content is removed during repair.

What steps can reproduce the bug?

1. Use Codex to generate or refine a PowerPoint presentation and export it as a .pptx.
2. Save the generated file as:

generated_presentation_ascii.pptx

1. Open the file in Microsoft PowerPoint.
2. Observe that PowerPoint does not open it normally and instead shows a repair prompt.
3. Click Repair.
4. Observe that PowerPoint reports unreadable content was repaired and removed.

What is the expected behavior?

The generated .pptx should open in Microsoft PowerPoint without any repair prompt, and no content should be removed.

Additional information

• I searched existing issues in openai/codex and did not find one matching this specific PowerPoint repair-dialog failure mode.
• This appears distinct from issue #15427, which is about artifact runtime release availability rather than malformed PPTX contents.
• If useful, I can provide:
• the generated .pptx
• the exact prompt used to generate or refine it
• the PowerPoint repair log XML, if PowerPoint produced one
• screenshots of the repair dialogs