I receive this error on some or all of my DNN site pages.

! A critical error has occurred.
The device is not ready.

This problem has been fixed with the following information provided in the following DNN forum posting:

http://www.dotnetnuke.com/Community/Forums/tabid/795/forumid/54/threadid/257600/scope/posts/Default.aspx

Excerpt:
...you MUST log in using the Host account, then go to the module settings page and at the bottom you will see where you can specify the physical location of the Repository files. Set the location to match your local drive and path to the files.

The physical location of the repository of files will generally be something like E:\inetpub\vhosts\yourdomain.com\httpdocs, but may vary slightly depending upon which 3Essentials server you are hosted on and where in your directory structure you deployed your DNN installation.  Please submit a support request if you need help determining the physical location of your DNN repository files, and please reference this KB article number in your submission.