I see the following error after upgrading to rails 3.2.12 with ruby 1.9.2.
ActiveRecord::Fixture::FormatError: a YAML error occurred parsing /SampelRails/user_properties.yml. Please note that YAML must be consistently indented using spaces. Tabs are not allowed. Please have a look at http://www.yaml.org/faq.html The exact error was: Psych::SyntaxError: couldn't parse YAML at line 1 column 0
I have doubled checked the yml files and they seem to be indented properly.
according to https://github.com/rails/rails/issues/2731 this issue seem to be fixed in rails 3.1.1.