Trying to change the validity of a subkey results in an (non permanent) error.
- Choose the subkey
- Choose "change validity" (You see the "valid until" field is prefilled with today +3 years)
- Choose radio button "valid until" and select the date-chooser.
- Immediately an error is shown, complaining that the date must not be after the validity of the primary key.
Please prefill the "valid until" field with the validity of the primary key, if this is less than 3 years in the future.