If you’ve encountered problems with PSE 11 or 12 in Yosemite, the latest version of Apple’s operating system, there’s finally a fix. Just update to 10.10.1 and that should fix things for you. If you installed the plugin that Adobe made available as an interim fix, be sure to remove it. The file path would be:
Applications->Adobe Photoshop Elements (version number)->Support Files->Plug-Ins
For more information, see Adobe’s help document:
http://helpx.adobe.com/photoshop-elements/kb/pse-stops-responding-yosemite.html