So I am in the middle of a new project and I needed to upload an OVF to vCloud Director. I downloaded and installed the Client integration plugin Several times with no luck. I finally found the following workaround:
Download Firefox ESR 52 32bit version from here:
Download and install the plugin:
You should now be able to upload an OVF

Or learn to use the CLI ovftool, and it’ll probably go 10 times quicker..