Diagnosis
You have attempted to delete a fixed wage type.
The wage type model, which is set to 'F' in the view, was assigned inthe Basic Pay infotype and cannot be overwritten.
The view for the Basic Pay infotype (0008) is V_T539A "Default wagetypes for basic pay".
The view for the Wage Maintenance infotype (0052) is V_T539R "Wagemaintenance".

Procedure
The wage type cannot be overwritten. If you want to change thissetting, modify the entry in the customizing system accordingly.