Failed option flags

I’ve got some issue here with Duplicati, in the log files it keeps giving me the following;

Failed: Setting multiple retention options (--keep-time, --keep-versions) is not permitted
Details: Duplicati.Library.Interface.UserInformationException: Setting multiple retention options (--keep-time, --keep-versions) is not permitted
  at Duplicati.Library.Main.Controller.ValidateOptions () [0x000ab] in <60a7e79acb3b49e8af8a73149919d15b>:0
  at Duplicati.Library.Main.Controller.SetupCommonOptions (Duplicati.Library.Main.ISetCommonOptions result, System.String[]& paths, Duplicati.Library.Utility.IFilter& filter) [0x004f0] in <60a7e79acb3b49e8af8a73149919d15b>:0
  at Duplicati.Library.Main.Controller.RunAction[T] (T result, System.String[]& paths, Duplicati.Library.Utility.IFilter& filter, System.Action`1[T] method) [0x00072] in <60a7e79acb3b49e8af8a73149919d15b>:0

I never set --keep-time and/or --keep-versions together, I only set one of these option and that was just --keep-versions I checked my config and it doesn’t even have both of these settings enabled, only one of them. How can I force it to recognise from the config that only one of them is set and not both? I only want/need --keep-versions for keeping backups of up to 3 months at a time.

How? Especially because there can be a merge from Default options in Settings, a good method is to use Export As Command-line. You can then use browser search tool on the screen, e.g. search for keep.

Another way to check is to use the Commandline button then look for the section where keep options are.

If you want time-based, why do you prefer a keep-versions guess over keep-time asking for 3 months?