Photoshop: Some of the application components are missing from the Application directory.

I have had and used PS CS5 Extended version 10.6.8 since about 2010 which I received as a gratis replacement from Adobe as a DOWNLOAD when my originally purchased CS5 DVD (also from adobe) was found to be invalid because the CS4 was purchased (believed to have been as an upgrade CS4 Extended version 1-2 years prior) as a DVD (hard copy).
 
Adobe believed that the CS4 program was invalid but the use of the CS4 serial number had been accepted as bonafide when I ordered and purchased the new upgrade CS5 program.  A short time later, ADOBE sent me an email or a letter stating they would resolve the problem by setting us up, Bentley Licensing Group, LLC, with a fresh download of a new CS5 Extended version but with no hard copy but would program it so that if "the position of the CS5 symbol in the DOCK moved (indicating ? another program ?), I would get a warning "THE POSITION OF YOUR ADOBE CS5 HAS MOVED TO ANOTHER POSITION.  DO YOU WANT TO PUT IT BACK TO WHERE IT WAS?  This would often happen after a crash.  I would answer YES, and everything would start working again.

That is, until Friday March 16, 2018, when it CRASHED just before it was ready to finishing loading a "save as" of a STN large file.  The crash data lasted only a few seconds at best, then disappeared together with the PS symbol in the dock.  I could have missed the warning that could have been hiding behind other pages on the screen.  I believe i found the Icon that belonged in the dock but when I tried using it, the following warning came up:  PS some of the applications components are missing from the Application directory.  Please reinstall the application.  I am unable since I don't have that depth of knowledge but I do have many components listed under CS5 in the Applications Folder.

This is the first time I am using this Community powered support.  It took a while to find it. Thanks for your help getting us back in business.