As a matter a fact, the error is related to the validation itself. It
'crashes' on the relation category-classified.
So far I found out that the error is introduced in chapter 5 after
adding the relation category-classified. It has nothing to do with file
If you remove the validations from the model it all works fine.
So far, the author hasn't come back with an answer to fix it.
Ideally, you should be able to trap the errors
Anybody got an idea how to overcome this? APparantly, the Ruby code
tries to retrieve associated records from a category, without having an
instantiated classifieds array.