The members data collection is part of the Wix Members area and is created automatically when you add the members area. A custom CMS collection you have created will not be recognized by these API’s.
If you have added the members area and are still seeing this error, you can read how to report a bug here Wix Studio - How to report a bug
in addition wix-users is deprecated and i would suggest using the wix members api Velo Wix Members Backend Introduction | Velo