After trying to add new field collection item, I get this message in Chrome when going back to the previous page in browser:
Notice: Undefined offset: 92 in field_collection_field_widget_embed_validate() (line 1675 of /sites/all/modules/field_collection/field_collection.module).
and when I tried to save I got this:
EntityMalformedException: Missing bundle property on entity of type field_collection_item. in entity_extract_ids() (line 7734 of /includes/common.inc).