First image is saying that Position number which has been entered is not exist in table T528B i.e either you have created position in OM but not updated in PA table so you have to execute RHINTE report then it will appear in T528B as well further enable the PLOGI ORGA integration switch so that it updates the table no need of executing report for other positions which you will be going to create or you have not created that position in OM so it is saying that does not exist.
Similarly second one as well you have not created subgroup but you are trying to assign number ranges for it so pick the right sub group or else create that sub group.
Regards
Venkatesh