For some reasons I'm having this error appears in my dashboard
Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, 'admin_init' was given in /home/devromot/public_html/wp-includes/plugin.php on line 405
has anyone came across that before? if so do you know where problem might be?
It seems you have a plug-in or theme activated which is trying to hook a function onto the admin_init hook, but the the function name they've given is not valid. Usually because the function doesn't exist, and potentially because they've put a space in the callback name.
Try deactivating your plug-ins/ themes one by one to identify which one it is. Then you'll just have to find the offending hooked function and work out why the name they've hooked onto admin_init invalid.
