[Plugin: Custom Post Type UI] Warning: Illegal offset type in isset or empty

Hi all,
there’s a warning displaying in my website after creating some custom taxonomy with custom-post-type-ui plugin. The warning is the following:

Warning: Illegal offset type in isset or empty in /public_html/clients/farmadeals/wp-includes/taxonomy.php on line 211
array(1) { ["invalid_taxonomy"]=> array(1) { [0]=> string(16) "Invalid Taxonomy" } } array(0) { }

It seems that the plugin is causing this issue. What should I do to fix it? Could you help me please?

http://ww.wp.xz.cn/extend/plugins/custom-post-type-ui/