In this article, we shall discuss how to fix “Faulting application name: mmc.exe: Unable to launch ADUC (Active Directory User and Computer) “. The application mmc.exe may be faulty when using Active Directory Users and Computers for various reasons such as corrupted system files, incompatible third-party software, insufficient system resources, misconfigured group policies, or issues with the Active Directory database. Please see “Allow RDP access for non administrators: Add User to Remote Desktop Users Group in Active Directory“.

Note: Reinstalling Remote Server Administration Tools (RSAT) directly on a domain controller (DC) is not recommended or supported. Instead, for a domain controller, you should focus on troubleshooting and repairing the existing installation. For this to even work at all, you will have to demote the Domain Controller and this is what you do not want.

Active Directory Users and Computers (ADUC) is a Microsoft Management Console snap-in that you use to administer Active Directory (AD). In my case, the MMC Snap-ins (ADUC) Loads but fails to launch.

Here is a guide on “Azure AD Connect Permission issue: Error 8344 insufficient access rights to perform the operation“, and “How to Fix “Insufficient System Resources Exist to Complete the Requested Service” error“.

Error Prompted “Faulting Application Name: mmc.exe”

I suggest not rushing to the internet to look for a solution without truly understanding your environment. On the internet, numerous answers suggest modifying the TCP/IP parameters. But this is not the same as you can see from the error messages below.

Another relevant log is below “APPCRASH”

Please see How much RAM does your Windows PC really need?, How to save and stop modification to Microsoft Management Console, and How to save and stop modification to Microsoft Management Console.

Reason for ADUC Crash: Insufficient System Memory

For me, insufficient system memory was the root cause of this issue “Microsoft Management Console for Active Directory Crash. But why could this be so?

When you launch MMC with Active Directory snap-ins, it consumes system memory to load the necessary components and data structures. If there isn’t enough memory available, the loading process will fail as shown in the error above.
Active Directory MMC snap-ins deal with a significant amount of data related to user accounts, group policies, organizational units, etc. Insufficient memory will hinder the processing of this data, leading to sluggish performance or crashes in my case.
MMC requires a certain amount of memory to operate efficiently. If the system is low on memory, other processes competing for resources may cause MMC to encounter memory allocation failures or memory leaks.
MMC utilizes memory for caching frequently accessed data to improve performance. Insufficient memory limits the size of this cache, potentially impacting the responsiveness of MMC and leading to performance degradation/crash.

To address issues related to insufficient system memory, you can try closing unnecessary applications to free up memory or adding more RAM to the system. Issue of memory leaks can also be invested as we have been affecting the AD environment recently.

The solution to MMC APP CRASH

Previously, I had 1GB assigned, and this was increased to 2GB but the issue wasn’t resolved. Ensure Sufficient System Resources as insufficient system resources memory can cause MMC and Active Directory issues in general. Check the server’s resource usage and ensure it meets the requirements. As you can see below, the server memory has been increased to 3GB.

Here, the 3GB signifies the total RAM available and 1.6GB is currently being actively used by running processes etc. The 1.7 GB committed out of 3.6 refers to the total amount of virtual memory (RAM + Pagefile) that is committed by running processes and the operating system. In this case, 1.7 GB of memory has been committed, which includes both physical RAM and space allocated on the pagefile. The total committed memory, including the pagefile, is 3.6 GB

Note: If the available memory gets too low, it could lead to performance degradation as the system may start to rely more heavily on virtual memory stored in the pagefile, which is slower than physical RAM.

See How to fix this computer is a domain controller: The snap-in cannot be used on a domain controller, and how to Run Android Apps on Windows with BlueStacks.

Increase VM RAM Size

To do this, right-click on the VM and select settings. You can use the Actions Pane as shown below as well.

Click on Memory and increase the size to 3072MB.

Launch Active Directory User and Computer

Try to launch the ADUC snap-in once again

You should be able to access the snap-in right now without issues.

Active-Directory-User-and-computer-snap-in

Note: If the issue persists and is specifically related to Active Directory, consider running tools like DCDiag or repadmin to diagnose and repair any Active Directory-related problems.

I hope you found this article on “Faulting Application Name: mmc.exe: Unable to launch ADUC’ very useful. Please feel free to leave a comment below.