Twitter API wants lists names with spaces in them to be hypen-separated and won't accept their corresponding URLencoded value. The spaces should be replaced by hypens before calling the API.
It may be wiser to use alternate parameters to make this call, such as the list identifier rather than the name. However, that would require a refactoring. In all likelihood users don't have two identically named lists, one with hyphens and one without, anyway.
Twitter API wants lists names with spaces in them to be hypen-separated and won't accept their corresponding URLencoded value. The spaces should be replaced by hypens before calling the API.
It may be wiser to use alternate parameters to make this call, such as the list identifier rather than the name. However, that would require a refactoring. In all likelihood users don't have two identically named lists, one with hyphens and one without, anyway.