Dropbox backup creation


I have created a automated dropbox backup creation and it is configured for interval of daily. And i have given the mail id to send the backup status.

Yesterday night i have recieved an backup error mail.

Backup Upload FailedOops, your automated backup to Dropbox
Error message:
Traceback (innermost last):
File “/home/frappe/frappe-bench/apps/erpnext/erpnext/setup/doctype/backupmanager/backupmanager.py”, line 33, in takebackupsdropbox
didnotupload, errorlog = backuptodropbo)
File “/home/frappe/frappe-bench/apps/erpnext/erpnext/setup/doctype/backupmanager/backupdropbox.py”, line 92, in backuptodropbox
response = dropboxclient.metadata(“/files”)
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/dropbox/client.py”, line 891, in metadata
return self.restclient.GET(url, headers)
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/dropbox/rest.py”, line 311, in GET
return cls.IMPL.GET(*n, **kw)
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/dropbox/rest.py”, line 246, in GET
return self.request(“GET”, url, headers=headers, rawresponse=raw_response)

line 227, in request
raise ErrorResponse(r, r.read())
ErrorResponse: [400] u"App folder (sandbox) access attempt failed
because this app is not configured to have an app folder. Should your
access type be ‘dropbox’ instead?"

    Please contact your system manager for more information.

May i know what i have to change and where i have to change

Please look up dropbox api help.