Obout Treeview Version issue

I just tried to install the Obout Treeview control on a page in my site using the same ASP.NET code provided in the knowledge base. I've done what the KB article recommended and downloaded the latest "TreeIcons" directory from Obout's website.

When I try to run the code, I get the following Javascript alert message: "Property 'FolderIcons' has the wrong path or file 'ob_tree_505.js' is not there"

I believe this is a version issue, because the javascript file(s) I downloaded from obout.com in the "TreeIcons" folder are named similarly to the above name, but with a different version. That is, I've got 'ob_tree_2021.js' in my ~/TreeIcons/Icons directory.

Am I missing something? What version are the Obout TreeView DLLs on the server? How do I obtain the "505" versions of the .js file?