500 Error when setting up Windows Azure Pack

I am putting this out there so the next person doesn’t have to spend the DAYS I wasted trying to fix this. Here is the story:

You want to install SMA on your brand new Windows 2016 Server, but obviously need Windows Azure Pack. Grab the web installer, fire it up, verify that you have the right pre-reqs, and pick the Windows Azure Pack Express and Admin API selection. The install goes fine, and a web page will launch so you can configure Azure Pack. You enter your database info, user and passphrase info, and ‘next’ your way to the end. You press that last checkmark and expect all of the little circles to come back green……but then you see that the Admin Authentication Site has come back with an error:

“500 Internal Server Error – Failed to configure databases and services: Some or all identity references could not be translated.”

Long story short – Go to your inetpub directory, and pull up the properties on the folder named “MgmtSvc-WindowsAuthSite”. Un-check the Read-Only box at the bottom, apply, and when prompted tell it apply to all sub-items.

From what I can tell – the connection strings and users you entered during the config are entered into the webconfig for this site. My guess is that the setup program is attempting to decrypt the webconfig and create additional files (an un-encrypted version of the webconfig?) but was failing due to the read-only property. I can’t verify that (I refuse to go through that setup program again), but I do know that unchecking that box finally got the config to complete successfully, I was able to finally launch the Service Management Portal, and get my SMA web service registered.

The literal days I wasted on this – I hope none of you have to go through that.