Site-wide Categories won't work until you add categories. Add categories now.

Hi,

I have installed most latest elgg version and enabled "Site-wide Categories" plugins. I have been trying to save such Categories "Colleges, Universities, Institutes" and save it but its not saving and always prompting me the following message...Any help???

"Site-wide Categories won't work until you add categories. Add categories now."

And few other times, I get "The page you were using had expired. Please try again"