After updating from 4.1.2 to 4.1.3 I recieved the following errors on the page edit screen for the Page Link fields:
Warning: in_array() expects parameter 2 to be array, null given in /wp-content/plugins/advanced-custom-fields/core/fields/post_object.php on line 114
Warning: Invalid argument supplied for foreach() in /wp-content/plugins/advanced-custom-fields/core/fields/post_object.php on line 120
I tested the Page field both in and out site of a repeater field and was getting the same error.
It would appear in the $field['taxonomy'] value is not an array. So to resolve the issue I modified the following lines
/advanced-custom-fields/core/fields/post_object.php on line 114
if( ! in_array('all', (array) $field['taxonomy']) )
/advanced-custom-fields/core/fields/post_object.php on line 120
foreach( (array) $field['taxonomy'] as $v )
Not sure if this is the best solution but it resolved the issue for me.
Hope this helps