There is a bug that currently allows invalid values to be imported to field collection fields. For example, when importing an Animal, you can give it a "Tag type" that doesn't exist in the system. This only happens with fields inside Field Collections.
I reported this in the Field Collection issue that provides Feeds integration: #1063434: Add Feeds integration to FieldCollection
Here is my comment specifically: https://www.drupal.org/node/1063434#comment-12203562
It should be fixed in that issue, but I decided to create this issue in the farmOS queue so that we don't forget about it.
Here is the Feeds issue that added field validation: #2379631: field_attach_validate() must be called before programmatic entity saves
Comments
Comment #2
m.stentaComment #3
m.stentaSpecific instances where this is an issue:
Comment #4
m.stentaWe don't use Field Collections in farmOS 2.x - and this won't be fixed in 7.x-1.x.