Backups failing with 403 error


I am trying to back up to a S3 compatible service from Contabo and am getting the following error on every backup I try:
System.AggregateException: One or more errors occurred. —> System.AggregateException: The remote server returned an error: (403) Forbidden. —> System.Net.WebException: The remote server returned an error: (403) Forbidden.
at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at System.Threading.Tasks.TaskFactory1.FromAsyncCoreLogic(IAsyncResult iar, Func2 endFunction, Action1 endAction, Task1 promise, Boolean requiresSynchronization)

Can anyone point me in the right direction please?


either there is a compatibility problem, or your parameters are not correct.
Try to use the backend tool (Duplicati.CommandLine.BackendTool.exe):

particularly the LIST command and the --debug-output command line switch (that will provide you the maximum information). Export the job as command line to get more easily at a connection string. If the LIST command works (try to add a file manually with the provider interface and see if you can see it), try a PUT (if you don’t have write rights, it will fail even if LIST works).