What i do :

  1. Open user profile which membership role i want to change
  2. Choose role
  3. Press "Update membership"

What i get:

Warning: array_merge(): Argument #1 is not an array in field_default_extract_form_values() (line 39 of /home/devel/arendus/modules/field/field.default.inc).
Recoverable fatal error: Argument 2 passed to drupal_array_get_nested_value() must be of the type array, null given, called in /home/devel/arendus/modules/field/field.default.inc on line 41 and defined in drupal_array_get_nested_value() (line 6711 of /home/devel/arendus/includes/common.inc).

The website encountered an unexpected error. Please try again later.

Result:
role not changed, site shows only error

I am using lates open atrium.