Triggered Alarms cannot be reset to green in vCenter Server

Products

• VMware vSphere ESXi

Issue/Introduction

In the vSphere Client, certain triggered alerts/alarms may remain active and cannot be cleared manually. 
The Reset to Green option appears greyed out or unavailable for the triggered alarm, even when the underlying condition has been addressed.

Environment

VMware vCenter Server 8.x

Cause

The alarm state synchronization between the alarm definition and the triggered instances can occasionally become desynchronized, causing the management options (like Reset to Green) to become unresponsive in the UI.

 

Resolution

To restore the ability to reset the alarm, you must toggle the alarm definition to refresh its state:

1. Log in to the vSphere Client.
2. Navigate to the object where the alarm is triggered (e.g., vCenter, Datacenter, or Host).
3. Click the Configure tab and select Alarm Definitions.
4. Search for the specific alarm that is stuck.
5. Select the alarm and click Disable.
6. Wait a few moments, then select the alarm again and click Enable.
7. Navigate back to the Monitor tab and select Triggered Alarms.
8. Select the stuck alarm; the Reset to Green option should now be available. Click it to clear the alert.