[Plugin: Cimy User Manager] CIMY User Manager Export Issue

I am converting a site from WP 2.33 to 3.01 by rebuilding most of it instead of incrementally updating it. I thought that I would install CIMY User Manager to export the users from the 2.33 version then import into the 3.01 version.

I select the following choices:

Use , as a the delimiter
I select the Option to export extra fields used by User Extra Fields
I don’t change the date parameters
Click Export
I get the screen that lists all of the exported users then try to download the file but I get this error:

Fatal error: Call to undefined function: admin_url() in /homepages/16/d231095444/htdocs/wp-content/plugins/cimy-user-manager/cimy_user_manager.php on line 71

What’s happening?