Re: I just installed MacOS X Yosemite on my MacBook Air 2011. After installing Yosemite I installed the Photoshop Elements 12.1 upgrade, but now when I open the program and try to use the tools, the program freezes. How do I fix this problem?

If you use a trackpad and don't want to switch to a mouse, you can uninstall and reinstall all day long and will still have problems, but if you really want to try it, you can download PSE 12 here:

Download Photoshop Elements products | 12, 11, 10