Before we start discussing about the problems due to which you may face a problem when Editor stops working, let's have a look at following forum threads -
The very first suggestion given can be found about deleting preferences. Let's see the detailed steps to do the same...
1. Close Adobe Photoshop Elements Editor.
2. Launch the Photoshop Elements Welcome Screen and hold down ctrl + alt + shift as you click Edit.
3. Continue to hold the keys until you see a message box asking if you want to delete Photoshop Elements settings file...
4. Click Yes. Adobe Photoshop Elements will open with default preferences.
This is one of the very first step when you encounter any known issues with Editor. Even if this doesn't work for you, Please comment here with exact problem and we shall try to resolve it.