Unable to activate - Mainfest conflicts reported in event viewer (EventID=78)

Environment: Windows 8.1, 64-bit Windows system. Acrobat Pro XI was installed, but with the end of support for it I purchased Acrobat DC (version 12). Ran the installer from Adobe media (which uninstalled the old Acrobat) which completed without error messages. Opening Acrobat after a reboot I get the expected requirement to log in for activation which I did, then arrived at the EULA screen. Clicking "accept" causes the activation application to close.

The event log records an event ID 78 reporting a side-by-side error:

Activation context generation failed for "C:\Program Files (x86)\Adobe\Acrobat 2015\Acrobat\Acrobat.exe".Error in manifest or policy file "" on line . A component version required by the application conflicts with another component version already active. Conflicting components are:. Component 1: C:\Windows\WinSxS\manifests\amd64_microsoft.windows.common-controls_6595b64144ccf1df_6.0.9600.18006_none_623f33d3ecbe86e8.manifest. Component 2: C:\Windows\WinSxS\manifests\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.9600.18006_none_a9ec6aab013aafee.manifest.

This is the same as I found in postings from last summer, differing in the event ID (I see ID 78; the other postings ID 80).

Error in manifest or policy file "<missing-file-name>" on line <missing-line-number>.

I've tried the workarounds posted by "Rave" (Adobe staff) in several places (see e.g., https://forums.adobe.com/message/7597219 ) and none of them worked. We do run EMET (version 5.2) but temporarily removing it did not resolve the problem.

Another suggestion in that same thread was from "Dpakch" (also Adobe staff) suggested downloading a replacement manifest file from acrobat.com:

https://files.acrobat.com/a/preview/efe766ae-a963-4303-950e-e43f1976aef1

but that link no longer works.

Several of the postings indicated that the problem was a flawed manifest (as noted above, editing it did not help).

The disk I have is Adobe p/n 91098219 dated January 2015.

This problem may be restricted to Windows 8.1; another staffer installed Acrobat (from the same disk) on a Windows 7 64-bit system and it works without problems.

Since I can't activate the product (and thus cannot install updates) it's worthless to me until it's fixed. HELP!