After some maintenance work performed in ESXi server side, monitors for ESXi server (such as "VMCount") no longer work. It was working before ESXi server side maintenance.
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Environment
vmware probe ANY version. Static monitor (Not auto monitor) is used.
Cause
VMware ESXi Host's UUID was changed by the maintenance. Since static monitor uses internal ID to track object, it does no longer work after the internal ID is changed.
1. This is how to confirm ESXi server HOST's UUID.
https://<host>/mob/?moid=ha%2dhost&doPath=hardware%2esystemInfo Where <host> is your ESXi server host's IP, shortname or FQDN.
2. You may want to consider using "Auto Montior" rather than "Static Monitor" Auto Monitor does not use an internal ID to track object. Please take a look at the below KB to understand advantages and disadvantages of Auto Monitor.