master suite cs5

Dear All,

I can't copy and paste selected areas on images in Photoshop CS5 (Yosemite 10.10.5), neither can I copy and paste (or drag) any and all layers onto another new file (they don't show on the new file).

I've cleaned preferences, installed Java for OS X 2015-001 a few times, restarted my iMac, still no help.

I uninstalled Adobe Photoshop CS 5 and installed it from link below, but my Master Suite serial number doesn't work for it (it's authentic copy)  Download CS5 products

I couldn't find CS5 Master Suite Uninstaller anywhere in Applications. I tried to install from my own original CD, I can't find installer file at all! Now it's all messed up! I'm left without Photoshop. Anyone please help! Thank you!