Warning if i try to unistall (for reinstalling) nice messages

I was trying to unistall 7.x-2.1 NM cause it doesn't work in 'save/update/etc pages message' and reinstall a fresh 7.x-2.1+2-dev version.
But while uninstalling i get this warning messages .

Is it a bug or this behaviour depends on something else?

	•	Warning: Illegal string offset 'field_name' in field_delete_instance() (line 772 of /Applications/MAMP/htdocs/test-site/modules/field/field.crud.inc).
	•	Warning: Illegal string offset 'entity_type' in field_delete_instance() (line 773 of /Applications/MAMP/htdocs/test-site/modules/field/field.crud.inc).
	•	Warning: Illegal string offset 'bundle' in field_delete_instance() (line 774 of /Applications/MAMP/htdocs/test-site/modules/field/field.crud.inc).
	•	Warning: Illegal string offset 'field_name' in field_delete_instance() (line 781 of /Applications/MAMP/htdocs/test-site/modules/field/field.crud.inc).
	•	Warning: Illegal string offset 'id' in conditional_fields_field_delete_instance() (line 1543 of /Applications/MAMP/htdocs/test-site/sites/all/modules/conditional_fields/conditional_fields.module).
	•	Warning: Illegal string offset 'id' in conditional_fields_field_delete_instance() (line 1544 of /Applications/MAMP/htdocs/test-site/sites/all/modules/conditional_fields/conditional_fields.module).
	•	Warning: Illegal string offset 'field_name' in image_field_delete_instance() (line 480 of /Applications/MAMP/htdocs/test-site/modules/image/image.module).
	•	TypeError: Argument 1 passed to serial_field_delete_instance() must be of the type array, string given, called in /Applications/MAMP/htdocs/test-site/includes/module.inc on line 957 in serial_field_delete_instance() (line 75 of /Applications/MAMP/htdocs/test-site/sites/all/modules/serial/serial.module).