ESXi 9.1 Upgrade Triggers Temporary License Assignment Failed for this Host Warning

Products

• VMware vCenter Server
• VMware vSphere ESXi
• VCF Operations

Issue/Introduction

After upgrading ESXi hosts to version 9.1, the vSphere Client displays a warning banner stating: "License assignment failed for this host."

The following error sequence is observed in the vCenter vpxd and cis-license logs when the host rejects the legacy token format:

INFO vpxd #### [vc@#### sub="licenseClient" opID="HeartbeatStartHandler-########-########"] Assign license to host: '<HOSTNAME>'
WARNING vpxd #### [vc@#### sub="licenseClient" opID="HeartbeatStartHandler-########-########"] Failed request to VAPI service; Error:
-->    com.vmware.vapi.std.errors.invalid_argument
--> Messages:
-->    com.vmware.esx.licensing.entitlements.invalid_or_malformed_token<Invalid or malformed entitlement token.>
ERROR vpxd #### [vc@#### sub="licenseClient" opID="HeartbeatStartHandler-########-########"] License was unsuccessfully set on host: <HOSTNAME> with error: Error:
-->    com.vmware.vapi.std.errors.invalid_argument
--> Messages:
-->    com.vmware.esx.licensing.entitlements.invalid_or_malformed_token<Invalid or malformed entitlement token.>

Environment

VCF 9.1

VMware vCenter Server 9.1

VMware ESXi 9.1

Cause

During an ESXi host upgrade to version 9.1, a timing sequence mismatch occurs where vCenter Server initially attempts to push a legacy 9.0 formatted license payload to the host.

The upgraded 9.1 host rejects the legacy token due to new cryptographic signature requirements enforced by the 9.1 License Server appliance.

Resolution

• This issue will be resolved in an upcoming release.

• No administrative remediation is required to restore host licensing.

• Allow several minutes to pass after the ESXi host upgrade completes. The vCenter cis-license service will automatically fetch the updated 9.1 license format from the License Server and successfully apply it to the host in a subsequent synchronization cycle.

• Ignore the temporary warning banner in the vSphere Client during this automated synchronization period.