IT Support

Fixing Server Manager Error 0x800706BE: The Missing MUM/CAT Mystery | Lazy Admin Blog

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If your Server Manager is blank, showing a yellow bang, or refusing to refresh with a “Remote Procedure Call Failed” error, you aren’t looking at a network issue—you’re looking at a corrupted Windows Update store.

When Windows cannot validate the files in the C:\Windows\Servicing\Packages directory, the Server Manager discovery process crashes. Here is how to perform manual surgery on the CBS store to fix it.

The Symptom

  • Error Code: 0x800706BE
  • Event ID: 1601 (Microsoft-Windows-ServerManager/Operational)
  • Message: Could not discover the state of the system.

Step 1: The Diagnostics (CheckSUR)

First, we need to know exactly which files are broken.

  1. Download and run the System Update Readiness Tool (CheckSUR) (KB947821) or, on newer versions of Windows Server, run: DISM.exe /Online /Cleanup-image /Scanhealth
  2. Once finished, open the log file: %Systemroot%\Logs\CBS\Checksur.log
  3. Look for lines starting with (f) CBS MUM Corrupt or (f) CBS MUM Missing. These are your “targets.”

Step 2: Gain Control of the Packages Folder

By default, even an Administrator cannot write to the Servicing folder. You must take ownership:

DOS

takeown /F C:\Windows\Servicing\Packages /D y /R
icacls C:\Windows\Servicing\Packages /save %temp%\AclFile /T
icacls C:\Windows\Servicing\Packages /grant %username%:F /T

Step 3: Extract and Replace the “Grafts”

Now you need to “borrow” healthy files from the original Update files to replace your corrupt ones.

  1. Download the KB: Download the .msu file for the KB number listed as corrupt in your log.
  2. Expand the MSU: expand -F:* Windows6.1-KB978601-x64.msu C:\Repair
  3. Expand the CAB: Inside that folder, find the .cab file and expand it too: expand -F:* Windows6.1-KB978601-x64.cab C:\Repair\CAB
  4. The Extraction: Inside the CAB folder, find update.mum and update.cat.

Step 4: The Rename and Replace

This is where precision matters. You must rename those generic files to match the exact long string found in your Checksur.log.

  • Example Rename:
    • From: update.mum
    • To: Package_for_KB978601~31bf3856ad364e35~amd64~~6.0.1.0.mum
  • Move: Copy these renamed files into C:\Windows\Servicing\Packages.

Step 5: Verify the Fix

Close and reopen Server Manager. It should now trigger a fresh discovery without the RPC error. If it still fails, check the Checksur.log again—you likely have more missing packages to replace!

Lazy Admin Tip 💡

If you have another server running the exact same OS and patch level, you can often just copy the healthy .mum and .cat files from the “Good” server’s C:\Windows\Servicing\Packages folder to the “Bad” one. It’s much faster than manually expanding CAB files!

#WindowsServer #SysAdmin #ServerManager #Troubleshooting #ITOps #Microsoft #TechSupport #LazyAdmin #WindowsUpdate

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RDP Rescue: How to Fix Remote Desktop Issues Without a Reboot | Lazy Admin Blog

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If you can reach a server via ping or the VM console but RDP is failing, you can often “kick-start” the service by toggling specific registry keys. This forces the Terminal Services stack to re-read its configuration without dropping the entire OS.

1. The Firewall Check

Before diving into the registry, ensure the Windows Firewall isn’t blocking Port 3389. If you have console access, try disabling it temporarily to rule it out.

  • Quick Command: netsh advfirewall set allprofiles state off

2. The “Deny” Toggle (The Most Common Fix)

Sometimes the registry says RDP is allowed, but the service isn’t honoring it. Toggling the value can reset the listener.

Path: HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server

  • fDenyTSConnection: Should be 0. (If it’s already 0, change it to 1, refresh, then back to 0).
  • fAllowToGetHelp: Should be 0 to ensure Remote Assistance isn’t conflicting.

3. WinStation Listeners (RDP & Citrix)

If the main switch is on but the specific “listener” is disabled, you’ll get a “Connection Refused” error.

For Standard RDP: Path: HKLM\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP-Tcp

  • fEnableWinStation: Must be 1. Toggle this (1 -> 0 -> 1) to reset the listener.

For Citrix Servers (ICA): Path: HKLM\System\CurrentControlSet\Control\TerminalServer\WinStations\ICA-Tcp

  • fEnableWinStation: Must be 1.

4. Port Verification

Ensure the server is actually listening on the standard port. If someone changed the RDP port for “security,” your connection will fail.

Path: HKLM\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP-Tcp

  • PortNumber: Should be 3389 (Decimal).

Test it from your workstation: tnc <ServerIP> -port 3389 (PowerShell) or telnet <ServerIP> 3389

5. The Winlogon Block

In rare cases, the entire Winlogon station for terminal services is disabled at the software level.

Path: HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

  • WinStationsDisabled: Must be 0. If set to 1, no one can log in via RDP regardless of other settings.

Lazy Admin Tip 💡

If you can’t get to the console, you can change these registry keys remotely from your workstation! Open Regedit, go to File > Connect Network Registry, and enter the target server’s name. You can perform all the toggles mentioned above without ever leaving your desk.

#WindowsServer #RDP #SysAdmin #Troubleshooting #ITOps #TechTips #Networking #RemoteDesktop #LazyAdmin #ServerManagement

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