PLEASE HELP! AMA Extension Handler Status "Not Ready" - Guest Agent returning persistent 304, RuntimeSettings\0.settings never delivered despite clean reinstall

Based on the symptoms, focus on validating the Azure VM Guest Agent and the AMA extension lifecycle end to end on the affected VM, because AMA depends entirely on a healthy Guest Agent and extension pipeline.

Follow these steps in order:

1. Verify Azure VM Guest Agent health
   1. In the Azure portal, open the VM (WVDHOST-0) and go to Properties.
   2. Confirm Agent status is Ready and that the Agent version meets the minimum supported version.
   3. If Agent status is Not ready or blank, treat this as a Guest Agent issue first and resolve it before continuing, using the Guest Agent troubleshooting guidance.
2. Confirm Guest Agent services are running
   1. Use RDP to connect to WVDHOST-0.
   2. Open Services and verify the Windows Azure Guest Agent–related services (for example, WindowsAzureGuestAgent.exe / RdAgent depending on OS) are running.
   3. If Guest Agent isn’t running or is unstable, fix this first; AMA will not receive RuntimeSettings while Guest Agent is unhealthy.
3. Inspect Guest Agent logs for the AMA extension
   1. On the VM, open C:\WindowsAzure\Logs\WaAppAgent.log.
   2. Search for entries related to Microsoft.Azure.Monitor.AzureMonitorWindowsAgent.
   3. Confirm the following sequence exists:
      • Plugin environment setup, for example:

                [00000010] YYYY-MM-DDTHH:MM:SS.SSSZ [WARN] Setting up plugin environment (name: Microsoft.Azure.Monitor.AzureMonitorWindowsAgent, version: X.Y.Z.Z)., Code: 0
        

      • Plugin installation and success, for example:

                [00000010] YYYY-MM-DDTHH:MM:SS.SSSZ [WARN] Installed plugin (name: Microsoft.Azure.Monitor.AzureMonitorWindowsAgent, version: X.Y.Z.Z), Code: 0
        

   4. If these entries are missing, or show non‑zero codes, the Guest Agent is not completing AMA extension handling correctly. Address any Guest Agent errors first (disk space, RPC issues, Crypto permissions, etc.).
4. Check for common Guest Agent error conditions Use the Guest Agent troubleshooting checklist:
   1. Ensure the VM is Started and the OS is running.
   2. From a management machine, run portqry -n <VMName> -e 135 to verify RPC endpoints. If the CNGKEYISO process is missing from the RPC endpoints, start the CNG Key Isolation (KeyIso) service on the VM, then restart WaAppAgent.exe / WindowsAzureGuestAgent.exe.
   3. If WaAppAgent.log shows certificate import errors (for example, PFXImportCertStore failures), ensure the SYSTEM account has Full Control on:
      • C:\ProgramData\Microsoft\Crypto\Keys
      • C:\ProgramData\Microsoft\Crypto\RSA
      • C:\ProgramData\Microsoft\Crypto\SystemKeys
   4. If there are .NET BadImageFormatException errors, investigate and remove/adjust third‑party software that interferes with 32‑bit/64‑bit .NET processes.
   Any of these Guest Agent issues can prevent correct delivery of RuntimeSettings and keep the AMA handler in a Not Ready state even though the extension resource shows Provisioning succeeded.
5. Validate AMA extension files and status on the VM
   1. On the VM, go to C:\WindowsAzure\Logs\Plugins\Microsoft.Azure.Monitor.AzureMonitorWindowsAgent\{version}\.
   2. Open CommandExecution*.log and review stdout/stderr for install/enable errors.
   3. Go to C:\Packages\Plugins\Microsoft.Azure.Monitor.AzureMonitorWindowsAgent\*\Status\ and open *.status files.
      • Confirm that status is being written and sent to Azure.
      • If status files are missing or show repeated failures, the handler is not completing its lifecycle.
6. Confirm AMA processes are actually starting
   1. RDP into the VM and open Task Manager.
   2. On the Processes tab, verify the following are present and running:
      • AMAExtHealthMonitor
      • MonAgentHost
      • MonAgentLauncher
      • MonAgentManager
   3. If these four processes are running, AMA has started successfully even if portal status lags.
   4. If they are not running, treat this as an extension runtime failure and use the plugin logs from step 5 to identify the cause.
7. If the AMA extension is stuck or partially removed If logs indicate the extension is in a bad state (for example, missing manifest or incomplete uninstall), follow a clean removal and reinstall pattern similar to other VM extensions:
   1. From Azure, remove the AMA extension from the VM.
   2. On the VM, check C:\Packages\Plugins\ and remove any stale Microsoft.Azure.Monitor.AzureMonitorWindowsAgent folders if they remain after uninstall.
   3. Reinstall the AMA extension from the Azure portal and wait several minutes.
   4. Re‑check WaAppAgent.log, plugin logs, and Task Manager processes as above.

If, after confirming Guest Agent health, extension logs, and AMA processes, the handler still shows Not Ready while /vmsettings continues to return 304 and RuntimeSettings\0.settings is never applied, collect:

• WaAppAgent.log
• CommandExecution*.log for AMA
• *.status files for AMA

Then open a support case or post to the Azure Q&A forum with these artifacts, as recommended in the AMA troubleshooting guidance.

References:

• Troubleshoot Azure Monitor Agent installation issues on Windows VMs
• Troubleshoot Azure Windows VM Agent issues
• Troubleshooting tool for Windows guest agent: VM assist
• Troubleshooting the On-Demand Assessments (AMA)
• Troubleshoot CEF and Syslog via AMA connectors
• Troubleshoot Azure Arc-enabled servers VM extension issues