When you use the client-side object model to retrieve data from a custom column that is named "folder" in SharePoint Online, no results are returned.
To resolve this issue, change the name of the custom column to something other than "folder." Then, update the client application accordingly.
This issue occurs when you explicitly try to retrieve the value of the "folder" column.
Article ID: 2807697 - Last Review: Dec 28, 2016 - Revision: 1