Reinstallation Generated Problem ID: 15380, tried KB 114703 and KB 118079 with no success

This has been an involved and aggravating battle with this software.

I'm running Parallels 8 on a Late 2012 iMac with a 2.7 GHz Intel Core i5 with OS X El Capitan (10.11.2) across multiple admin user accounts. The initial installation offered little problem. However, after a couple of weeks' use, Parallels stopped communicating with the network, and the USB port. After the posted resolutions to these issues proved fruitless, I decided to just try reinstalling.

And now I can't even reinstall it.

The problem ID is 15380, and I've tried both of the posted solutions. Each user account has it's own unique ID, and none of them (except for root) are 0. The machine recognizes the admin account as admin.
What is going on? Am I trying to make a square peg fit into a round hole? Is this the foreseeable future for all attempts to make use of this software?

 

Hi GalleryH, Parallels Desktop 8 is not compatible with Mac OS X El Capitan and hence you are facing issues with installation. We suggest you to go for Parallels Desktop 11 for Mac, which is fully optimized for El Capitan.
Note: Parallels Desktop 8 for Mac is not eligible for upgrade to version 11. Please go for the full version.