Hi rmspmhc
63
In the download section of T4, there are different packages: Quickstart (used for new installation), Template package and plugin package.
If you already have an existing Joomla site, you should download template and plugin package, then install via Backend as other normal Joomla extensions.
The error you mentioned will appear when you try to install Quickstart package via backend or you may download all packages together, you need to unzip it first.
And I attach screenshot above so you can see that the image in forum still works.
Regards