A 'KeyError' exception ccurred during kickstart installation, why ?

Issue

• When performing kickstart installation, an un-handled exception occurred as below:

    Traceback (most recent call first):
      File "/usr/lib/anaconda/autopart.py", line 1243, in doAutoPartition
        for f in initial_free[drive]:
      File "/usr/lib/anaconda/dispatch.py", line 204, in moveStep
        rc = stepFunc(self.anaconda)
      File "/usr/lib/anaconda/dispatch.py", line 127, in gotoNext
        self.moveStep()
      File "/usr/lib/anaconda/dispatch.py", line 226, in currentStep
        self.gotoNext()
      File "/usr/lib/anaconda/iw/release_notes.py", line 86, in resize
        (step, args) = self.anaconda.dispatch.currentStep()
      File "/usr/lib/anaconda/iw/release_notes.py", line 51, in __init__
        self.resize()
      File "/usr/lib/anaconda/gui.py", line 1279, in __init__
        self.rnv = ReleaseNotesViewer(self.anaconda)
      File "/usr/lib/anaconda/gui.py", line 1108, in run
        self.icw = InstallControlWindow (self.anaconda)
      File "/usr/bin/anaconda", line 974, in ?
        anaconda.intf.run(anaconda)
    KeyError: 'sdb'