To try to insert slides into a blank presentation, follow these steps or make use of following resources where you can find different solutions for damaged PowerPoint documents
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1. On the File menu, click New, and then click Blank Presentation in the New Presentation task pane.
This creates a blank Title slide. You can delete this slide later after you re-create your presentation.
2. On the Insert menu, click Slides from files, and then click the Find Presentation tab.
3. Click Browse.
Select the damaged presentation, and then click Open.
4. Click Insert All.
If this operation is successful, all the slides from the damaged presentation, except the slide master, are inserted in the new presentation.
5. Save the presentation.
If your presentation does not look the way that you expect after you try these steps, try to apply the damaged presentation as a template. To do this, follow these steps:
1. Make a back up copy of your presentation.
2. On the Format menu, click Slide Design.
3. On the Slide Design pane, click Browse.
4. Select the damaged presentation, and then click Apply.
The slide master of the damaged presentation replaces the new slide master.