ACF Pro 5.3.6 Layout Title filter Breaks where the Flexible content is a subfield (say of a repeater)
https://cloud.githubusercontent.com/assets/67553/13776003/9d35953a-ea9f-11e5-8d4e-50012c5e7d1e.png
Seems that the line mentioned has $value = array_pop( $options[‘acf’][ $options[‘field_key’] ] ); which only works if the flexible content is a top level field.
I have reported this to the developer