This issue is observed on vCenter Server with uppercase GUID the remote plugin has issues to perform vCenter related operations. The following error message is found in the vSphere Client log:
[2022-11-17T07:25:59.406Z] [WARN ] http-nio-5090-exec-47 com.vmware.vsphere.client.rest.VcSessionShimController Plugin packageRef = com.acme:1.0.0.0, manifestUrl = https://<plugin-server-ip>:<port>/plugin.zip requested access to vCenter with GUID <vc-guid> which is not permitted.
The issue is observed on vCenter Servers deployed with version 5.5 and upgraded to a newer version. The remote plugin having problems to perform vCenter operations is using the incorrect format of the vCenter Server GUID. This means that on such environments where the vCenter Server is with uppercase GUID the remote plugin is using lowercase vCenter Server GUID when calling the clone ticket API.
To resolve the issue, please change the remote plugin which is requesting access using the clone-ticket REST API.
Please follow the solution depending on the actual implementation done in the remote plugin in question:
In case the remote plugin requires configuration for the vCenter Server GUID, then it should be configured with the correct vCenter Server GUID (case sensitive).
In case the remote plugin is transforming the vCenter Server GUID to lowercase, then the code should be modified so that it does not transform the GUID and uses the exact GUID (case sensitive) to request access.
To workaround the issue, the failing plugin can be hidden from the vSphere Client. This can be done in the Administration > Client Plugins.