Download and Install Photoshop CS5 I want to transfer a legal, licensed copy of Photoshop CS5 from and old Lion iMac I am de-commissioning to my current El Capitan system.  I have the license number, but not the install media as this copy of Photoshop started off as CS3 and then I did an online upgrade to CS5.  So I don't have CS5 install disks.

So I go to Download CS5 products and download the OS X install file for Photoshop CS5.  However when I went to run the installer I was presented with this:



Obviously something has gone wrong.  However I am not sure if this is an artifact related to not having Java 6 installed (See Will Adobe CS5 with Java SE runtime work on 10.11 El Capitan?) or if the file is actually hosed.  But Is it possible to use Adobe CS5 with Java SE 7? makes me think I should get past an install.

I don't believe that I have Java installed (and I only saw that question when I was composing this one), but I also don't want to have to jump through hoops to get CS5 up and running again.



Update - When I right click on the installer and select Show Package Contents I appear to be able to see the internals without any problem.
As per the comment from user3439894 the issue was that I had 


  System Preferences > Security &amp; Privacy > General > Allow apps
  downloaded from:


set to


  Mac App Store and identified developers


Once I set it to be


  Anywhere


Then I could run the installer.  

The error message I received was disingenuous and did not inform me of what the actual problem was.



Protip - Even though Adobe wouldn't tell me what my CS5 license number was there are ways to extract it from OS X.  It just took some googling.