“PowerPoint found a problem with content”

PowerPoint says “PowerPoint found a problem with content in Pitch.pptx. PowerPoint can attempt to repair the presentation. If you trust the source of this presentation, click Repair.” Sometimes Repair works; sometimes it ends with “Sorry, PowerPoint can't read”. Start with the free checks below, because often nothing is wrong with the file.

What usually causes it

The file is blocked. Presentations from email, the internet, Teams or a shared drive are marked as untrusted, and PowerPoint sometimes reports that as a content problem. The file opens fine elsewhere.
It's in a synced folder. A presentation opened from OneDrive, Dropbox or Google Drive while it's still syncing, or only partly downloaded, can trigger it.
Real damage. The save was cut short by a crash or a pulled USB stick, or a download stopped part-way. Big presentations with video and many pictures are more exposed because they take longer to save.
Something inside one slide. A broken embedded video, font, chart or add-in object can make PowerPoint distrust the whole file.

Free fixes to try first

Unblock it. Right-click the file → Properties, tick Unblock on the General tab if it's there, click OK.
Move it. Copy it out of OneDrive or Dropbox into a plain local folder such as Documents, and open it from there with File → Open.
Click Repair on a copy. If it works, PowerPoint says it removed unreadable content. Go through every slide before you rely on it.
Reuse Slides. Start a blank presentation, then Home → New Slide → Reuse Slides (or Insert → Reuse Slides), browse to the damaged file and insert the slides. This often works when opening the file doesn't, because only the slides are read.
Earlier versions. Properties → Previous Versions, or version history in OneDrive or SharePoint.
Another program. LibreOffice Impress, Google Slides or Keynote on a Mac sometimes open what PowerPoint won't.

When Repair doesn't work

PowerPoint's repair gives up when the file's table of contents is missing (it sits at the end of the file, so a cut-short save loses it first) or when the main presentation part is damaged. Office File Repair reads the file piece by piece instead. It recovers each slide it can read, replaces a lost slide master, layout or theme with a plain one so the slides still open, and rebuilds the presentation around the surviving slides. Pictures that survived are kept. The preview shows the recovered slide text before you pay, and nothing is uploaded.

The design of a recovered deck may look plainer if the theme was lost, but your slides and words come back.

When nothing can help

A 0 KB or all-zero presentation has nothing left in it (see file shows 0 KB). Slides that were stored after the point where a save was cut short are also gone. The tool can't open old .ppt files or password-protected presentations.

Common questions

Why does PowerPoint say it found a problem with content in a file that someone just sent me?

Most often the file is blocked because it came from email or the internet. Save it to Documents, right-click it, choose Properties, tick Unblock and open it again from PowerPoint.

What if PowerPoint's Repair doesn't work?

Try Reuse Slides: start a blank presentation, choose New Slide, Reuse Slides, and insert the slides from the damaged file. Then try earlier versions, LibreOffice Impress or Google Slides, and finally a repair tool that recovers slides one by one.

Is it safe to click Repair?

Yes, if you trust where the file came from. Do it on a copy and check every slide afterwards, because PowerPoint may remove content it couldn't read.

Will I lose my slide design?

Sometimes. If the theme or slide master was damaged, a repaired presentation can come back with a plain design. Your text and surviving pictures are what matter most, and you can apply a theme again afterwards.

Check your presentation: the preview is free