tag not working

Have you made any changes to your blog before you started to notice this problem, like any added or updated plugins, change of theme etc.

also, let us know your blog’s link,

looking foreword to your reply,

I regularly update plugins whenever update is available. pharmagalaxy.org

Have you tried:

– deactivating all plugins to see if this resolves the problem. If this works, re-activate the plugins one by one until you find the problematic plugin(s).

– switching to the Twenty Eleven theme to rule out any theme-specific problems.

– resetting the plugins folder by FTP or PhpMyAdmin. Sometimes, an apparently inactive plugin can still cause problems.

– re-uploading the wp-admin and wp-includes folders from a fresh download of WordPress.