Microsoft is planning to modify the Office 365 sign in process slightly by September 15th or October 1st and has kindly supplied advance notice and support for OnedriveMapper, but only for V3.29+ and V5.15+
V3.29 was just uploaded to Git, it fixes an issue where Microsoft no longer accepts the ‘ContentType’ header with GET requests to login.microsoftonline.com when set to “application/x-www-form-urlencoded”