I gave up on fixing the issue, since I was moving the application to a different server anyways; and it didn't look like any other applications were affected.
Then I restarted IIS, and all hell broke loose.
IIS was not starting back up; IIS Admin Service
was not starting with "Error 6: Handle is invalid".
That error helped me to get to the bottom of the issue, and find the correct permissions on the MachineKeys
folder.
This article pointed me to Default permissions for the MachineKeys folders - KB 278381 which had the correct permissions.
NOTE: KB article states that Everyone
should have Special Permissions
on This folder only
; yet sharepoint-geek's article suggests applying those permissions to This folder, subfolders, and files
(which I did).
Once the permissions were fixed, iisreset
worked and even my SSL issue was resolved.
Hope this saves somebody hours of frustration.