Please try couple of probable solutions as mentioned below:
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.
Solution 2: Try launching directly from exe 'PhotoshopElementsEditor.exe' from location C:\Program Files (x86)\Adobe\Photoshop Elements 11\ . Right click on this exe file at this location and select run as admin.
Solution 3: In case any network printer is attached try to launch without network or printer uninstall or make different printer as default.
Solution 4: Try launching with anti-virus off or removing PSE from conflicting list.
Unfortunately, nothing helped.
I tried to reinstall the program, but had message that serial number is invalid, although I put the right one (tried without/without spaces or dash).