Warnings when adding taxonomy term-field with checkboxes wodget

Steps to reproduce:

1) Normal installation profile
2) Add new vocabulary http://drupal7/admin/structure/taxonomy/add
3) Add some terms into new vocab - no breadcrumbs on edit vocab, and only vocab name on other pages :(
4) Go to manage fields admin/structure/types/manage/page/fields and add new "Taxonomy term" field with "Check boxes/radio buttons" widget
5) after submit on third (final) step field added but with:

    *  Notice: Array to string conversion in drupal_validate_utf8() (line 1152 of /var/www/d7/includes/bootstrap.inc).
    * Warning: preg_match() expects parameter 2 to be string, array given in drupal_validate_utf8() (line 1158 of /var/www/d7/includes/bootstrap.inc).
    * Notice: Array to string conversion in drupal_validate_utf8() (line 1152 of /var/www/d7/includes/bootstrap.inc).
    * Warning: preg_match() expects parameter 2 to be string, array given in drupal_validate_utf8() (line 1158 of /var/www/d7/includes/bootstrap.inc).
    * Warning: Invalid argument supplied for foreach() in options_buttons_elements_process() (line 135 of /var/www/d7/modules/field/modules/options/options.module).

6) Trying to delete this field and repeat step 4-5 I got WSOD at admin/structure/types/manage/page/fields/field_art/edit?destinations[0]=admin/structure/types/manage/page/fields

But field visible at admin/structure/types/manage/page/fields

WSOD on edit and node/add/page (db tables exists and does not clear after delete field)

Changing widget type brings everything work again, suppose problem with "Check boxes/radio buttons" widget