PowerPoint 2013 crashes when setting transparency on images
Certain JPG images may cause PowerPoint to crash if you attempt to set a transparent color on them.
If you're interested in the gory details, there's a LONG discussion thread about the issue on Microsoft Answers in the PowerPoint section. You can find that here.
If you're afflicted with the problem and just want to make it stop, skip the discussion and go here instead:
Note: This downloadable update only applies if you have an "MSI" version of Office 2013 rather than the more usual "Click-to-Run" version. If you have a Click-to-Run version, don't bother downloading the updates from this page.
How do you know which version you have?
Start PowerPoint and choose File | Account.
If there's an Update Options button on the right side of the screen, you have a Click-to-Run version of Office 2013. Unless you've turned updates off, the update will automatically install itself.
Look under Office Updates. It will tell you whether updates are being automatically installed or not, and will give you the current build version. If that's 15.0.4605.1000 or later, you have the "fix" for the JPG transparency problem.
If not, click Update Options and turn automatic updates on then click Update Now.