Hi Aloysius,
That error comes from a combination of two issues:
1. A translation of the error message with the key "lita.config.missing_required_adapter_attribute" is not available for the zh-TW locale. My understanding is that the i18n system is supposed to fall back to the default localization if a translation is not present. I don't know off hand why that didn't happen in this case. That makes it pretty confusing!
2. The English version of this error is "Configuration attribute "%{attribute}" is required for "%{adapter}" adapter." where the name of the missing attribute and the name of the adapter are interpolated. This means that the Lita adapter you're using requires a value for a configuration attribute that has not been set in lita_config.rb. Unfortunately the translation issue suppressed the default message so you weren't given information about which required attribute was missing.
A quick workaround would be to change the locale back to its default "en" so that you can see which configuration attribute is missing. A longer term fix would be to add the missing translation to a locale file for zh-TW. Debugging and fixing the i18n fallback behavior would also be a nice improvement.
Hope this helps,
Jimmy