RESOLVED!

1. I deleted the installed Image Store 3.3.0 plugin (which I had installed from within WordPress).

2. I reset the database.

3. I set the Settings/Media in WordPress

4. I DOWNLOADED a new copy of Image Store from the Image Store website.

5. I uploaded / installed the new copy of the plugin.

6. It all appears to be working correctly!

Thank you for a great plugin!