I was able to resolve it via the Manage Extension; there was an update there, which I installed that has now allowed me to use the upgrade wizard.
Thought, I post it incase anyone else runs into the issue.
Nikola
Telerik team
commented on 31 May 2024, 10:43 AM
Hello Nicholas,
I am glad that you were able to resolve the issue.
With the latest release of Telerik UI for ASP.NET MVC we have introduced breaking changes as we upgraded the target framework of the main assemblies to 4.6.2. This is described in the release notes.
This required changes in the Upgrade Wizard so we allow upgrades only when our assembly is compatible with the target framework of the project. So this is what could have happened in your case when the wizard was showing an error.
With the latest version everything is working as expected therefore I recommend always using the VS Extension version.