Try updating to 2.4 first.
Unfortunately no luck upgrading to 2.4 first, but I appreciate the suggestion. The same thing happened where the image file uploads but goes no further.
In case anyone else comes along looking for an answer to this same situation, I was able to get this working by going a different route.
I ended up creating a new vWLAN virtual machine using the OVA file and restoring my configuration onto that new setup. Downloaded a backup of my existing vWLAN configuration then powered down that VM so I could configure the IP addresses/networking on the new VM once the restore process was done. That worked successfully and was a quick/easy path so I'm all set with the latest version now.