Error in Step 3 "Create Blueprint" of the NetApp Shift Toolkit

[knerv]

An error occurred while using the Shift Toolkit, and I am unable to migrate the VM.

Problem Summary:
I installed the Shift Toolkit on a Windows environment.
After logging in, I followed the steps outlined in the documentation and
successfully completed Step 1, "Register Source and Destination," and Step 2, "Create Resource Group."
However, when I attempted to execute Step 3, "Create Blueprint," the "Configure Cluster and Host Mappings" screen
did not display the "Source Resources" or "Destination Resources" options that require selection. Clicking "Continue" triggers an error,
and I cannot proceed to the next step.

What are the possible causes of this issue?
The tested environment is as follows:

Source: VMware vSphere (vCenter Server 8.0.3, VMware ESXi 8.0.3)
Destination: PROXMOX Virtual Environment 9.1.1
ONTAP: ONTAP 9.17.1P6 (AFF A20) – Source VM deployed on an NFSv3 storage pool configured as a qtree

We are using Shift Toolkit 7.1.

We tested this in both the virtual environment and an on-premises Windows environment, and the results were the same.

Thank you for your assistance.

[knerv]

The original VMware vSphere environment was a standalone configuration consisting of a single ESX server that was not part of a cluster.
We used vCenter Server to create a cluster.

After adding the ESX server to the cluster, we attempted the migration again using Shift Toolkit, and the cluster name now appears on the "Source Resources" or "Destination Resources" screen of the blueprint.

[knerv]

I have one question.

With support from NetApp, we were able to create a cluster via the vCenter Server GUI and configure the blueprint.
Is the Shift Toolkit not compatible with standalone environments that are not configured as clusters?