Illegal string offset 'orderby'

I had this error too. I simply commented out the following lines in custom-taxonomy-sort.php and that seems to fix it (the fix may cause you other problems, but it’s been okay for me):

if (
			($args['orderby'] == $this->orderby_parameter && $args['order'] == 'DESC' ) ||
			($args['orderby'] != $this->orderby_parameter && $this->get_sort_order() == 'DESC' )
		) krsort( $ordered_terms );

In other words, comment out lines 328-331

@50 Seconds North

I experienced a similar error:

Warning: Illegal string offset ‘orderby’ in domain.com/wp-content/plugins/custom-taxonomy-sort/custom-taxonomy-sort.php on line 295

Commenting out the suggested lines 328-331 does not help here.

Is this a related issue ?

wordpress version: 3.5.1
custom-taxonomy-sort version 1.1.5

Turns out that if you switch from PHP5.3 to PHP5.4 the error on line 295 occurs.