This error occurs when there are some issues with Plugins on the system. When EO is launching it tries to fetch the plugins from two locations (for win7):
1. C:\Program Files (x86)\Adobe\Elements 10 Organizer\Plug-Ins
2. C:\Program Files (x86)\Common Files\Adobe\Plug-Ins\Elements 10
*** Version in above paths will change to PSE version installed on your computer.
As told already that this error occurs when there are some issues with Plugins. The issues can be-
1. Plugins are not present at their recommended locations.
2. Some plugins may be missing (may be removed by anti-virus or similar softwares).
3. Plugins gets corrupted.
To avoid getting this error message-
>> Uninstall PSE. Now close any anti-virus (or similar software) and re-install PSE.