I was trying to install Adobe CS5 in my Imac 2011 – running High Sierra. When i clicked on the installation icon, i always got “install” can’t be opened. you should eject the disk image.” , i verified my security setting, there is nothing blocked there.

This is the error i got:

 

Root cause: it’s something with Apple certificate expiration. It revokes Adobe from installing correctly.

This is how i fixed

Open “Terminal” appĀ  and run 2 commands below:

cd /Volumes/Adobe\ Photoshop\ CS5/Adobe\ Photoshop\ CS5/Install.app/Contents/MacOS/

install