Whats up??? Error 22: Window does not have a constructor. when i select photomerge / panorama on my imac. ( elements 11)
Try resetting the PSE preferences by
1. Close Elements.
2. Launch the Photoshop Elements Welcome Screen and hold down ctrl + alt + shift as you click Editor.
3. Continue to hold the keys until you see a message box asking if you want to delete Photoshop Elements settings file; click Yes. Elements will open with default preferences.
One of the similar threads is found here http://forums.adobe.com/thread/622755 which is for Photoshop but should work for PSE as well.