Unable to open SCCM admin console following 1511 upgrade

SCCM 2012 R2 SP1 with SCCM database on the same server.

So in a lab I upgraded my SCCM 2012 R2 SP1 instance to 1511. This is a Hyper-V environment running on my Surface Pro and I have SCCM, SQL and the SCCM admin console  running on the same VM.
The upgrade itself appeared to go smoothly but when I opened the admin console I just got the grey screen telling me I was unable to connect and that I should check I had permissions and that the SMS provider was installed and available, etc. Obviously it was, it was on the same machine and I had been working with it 20 minutes beforehand.

My immediate reaction was something had gone wrong with the DB upgrade. I hadn’t run the /TestDBUpgrade switch as this was very much a test environment and I didn’t have another server I could quickly and easily test it with. I did however take a snapshot and reverted back. A few tweaks here and there and a re-run of the upgrade produced the same result. Then I decided to test whether this was actually a problem with the installation or simply a problem with the console.
I decided to try and build a machine off this install (PXE boot) and sure enough it built perfectly.
Next, I installed the 1511 console on another VM (my lab DC in this case) and sure enough again, it connected perfectly.
Next step, check the console logs, in particular the SMSAdminUI.log file under C:\Program Files (x86)\Microsoft Configuration Manager\AdminConsole\AdminUILog. Under here I noticed that there were a number of performance counter errors eg as below:

[1, PID:844][04/08/2016 11:11:59] :The performance counter ‘# images’ was not found
[4, PID:844][04/08/2016 11:12:01] :The performance counter ‘# result objects in memory’ was not found
[4, PID:844][04/08/2016 11:12:01] :The performance counter ‘# exceptions’ was not found


Seems the upgrade broke the performance counter settings in some way so this needed fixing:
1. (Important) Open a command prompt and CD\Windows\SysWow64
2. LODCTR /R (ensure you are in the dir path above or you are likely to get error code 2).
3. Reinstall the console from the 1511 upgrade setup.
4. Et Voila, (hopefully) all should start working again.

The task sequence execution engine failed executing the action (Gather) in the group (State Restore) with the error code 2147942402…The operating system reported error 2147942402: The system cannot find the file specified.

Thought I’d do a quick post on this as there is precious little to be found in forums about this task sequence ‘bug’. I say bug, really it’s probably just lazy programming (I haven’t checked the specifics but the evidence leads me to believe this is the case).

Anyway…the scenario is this:

MDT 2013 U1

MDT-infused Client Task Sequence goes all the way through until it hits the Gather step under the State Restore phase. At this point you are hit with:

In this case the Set Variable For Drive Letter step under the Install section had set the OSDPreserveDriveLetter task sequence variable to TRUE which caused my OS disk to be set to X: for some reason! I suspect the same may happen if the OS had been installed on another drive other than C: but I haven’t tested this so can’t say for sure. Equally it appears to happen only with Gather Only Local Data. In any case the fix is to ensure you are installing to C: