Most of the time, they don't have Client account. They have an unlicensed software and didn't know that they need a verified account to download files from IPS.
it is part of the profits to own a legal license.
As mentionned on IPS website, You can convert from other community software with http://www.invisionpower.com/convert In your case , you just need to buy a Invision Power Board license to upgrade your community, It's simple,
If you need help you can contact Invision Power Support to help you, upgrading your board.
You have reached the main problem of using a nulled version of this great software.
90% of IPS products, hooks, themes that you can download for "free" have malwares, viruses that can damage your computer.
But in fact, there are also backdoors in these scripts, they can do what they want with your forum.
It's dangerous for you and .. your community members. Packagers of these nulled products can dump your database, spam your members...
It's a good choice to buy a license,
Now you will be able to download safe versions of the IPS Suite,
And you wil be able to view and download (latest versions of all products) on the Market Place .