The error code 0x0000009E is associated with the bug check message USER_MODE_HEALTH_MONITOR in Windows Server environments, particularly in failover clusters. It indicates a critical issue related to how the health of user-mode processes is monitored within a cluster.

Here’s a breakdown of the error and potential solutions specific to Windows Server clusters:

Understanding USER_MODE_HEALTH_MONITOR:

• In Windows Server failover clusters, a health monitoring mechanism ensures that critical user-mode processes (applications running in normal user mode) are functioning correctly.
• The 0x0000009E error signifies that the cluster service detected a user-mode process became unresponsive during a health check. This can lead to potential issues with failover functionality within the cluster.

Causes of USER_MODE_HEALTH_MONITOR:

• Faulty Applications: Applications with bugs or compatibility issues can sometimes hang or become unresponsive during health checks, triggering the 0x0000009E error.
• Software Conflicts: Conflicting software or drivers running on the cluster nodes can interfere with the health monitoring process.
• Resource Limitations: Insufficient system resources like memory or CPU usage on the cluster nodes can lead to application slowdowns or timeouts during health checks.

Troubleshooting Steps for USER_MODE_HEALTH_MONITOR:

Here are some steps you can take to try and fix the 0x0000009E error in a Windows Server cluster environment:

1. Identify the Failing Process:

   • Analyze cluster logs to pinpoint the specific user-mode process that failed the health check. This will help narrow down the source of the problem.

2. Update Applications:

   • Ensure all applications running on the cluster nodes are updated to the latest versions. Updates might contain bug fixes that address issues causing hangups or crashes during health checks.

3. Check for Software Conflicts:

   • Temporarily disable any recently installed applications or troubleshoot known software conflicts that might be interfering with the failing process.

4. Monitor Resource Utilization:

   • Use performance monitoring tools to track resource usage (CPU, memory) on the cluster nodes. Address any bottlenecks or resource limitations that could be causing application slowdowns.

5. Adjust Cluster Hang Recovery Action (Advanced):

   • Caution: This involves modifying cluster configuration settings. Proceed with caution and consult Microsoft documentation for detailed instructions.
   • You can adjust the cluster’s “HangRecoveryAction” setting to determine how the cluster responds to unresponsive user-mode processes. Options include logging an event, terminating the service, or causing a forced failover (not recommended).

Additional Tips:

• Keep your Windows Server cluster nodes updated with the latest security patches and hotfixes.
• Consider using cluster monitoring tools to proactively identify potential issues with applications or resource utilization.

Seeking Help:

If none of these solutions work, it’s recommended to consult Microsoft documentation or seek help from a qualified IT professional specializing in Windows Server clusters. They can delve deeper into the cluster logs, analyze specific application behavior, and suggest advanced troubleshooting steps to resolve the USER_MODE_HEALTH_MONITOR error within your specific cluster configuration.