I installed wordpress 2.0.1 first, some post and changed the theme also. But when tonight i try to create more category, incidentally nothing was happened there. Then i removed all thing and again reinstalling and update the new version 2.1.2 Wordpress theme. But again i gotcha same error Anyone have a same problem ? or its only with me?
Did you try running http://www.yourwebsitename.com/wp-admin/upgrade.php? If you just overwrote your 2.0 files with the 2.1 files, there will be an error. make sure you compare your old and new files. You need to delete some old files that weren't overwritten because 2.1 is using different name for some files.
Categories in the Wordpress sidebar are shown only when you make a post in that category! You can go ahead and make a hundred categories, but they will only display when there is atleast one post in that category. Abhishek
Thanks for your help, guys. Case solved . just deleted and install again the new version of wordpress theme ( i backed up my old data ), and its working now.