Hi Tina,
The error message indicates that the other members of your organization don't have the appropriate permissions to access your web maps in the field.
FYI, some background on the ArcGIS User Types: User types, roles, and privileges—ArcGIS Online Help | ArcGIS
I would check with your ArcGIS Online administrator and ask about the "user type" roles of your other members. If you want them to view the data in the field and edit data, for example in Collector for ArcGIS - they will need to be a 'Field Worker' user type.
Hope this helps,