Error 0x800720EC

Value: -2147016468 | 0x800720EC | 2147950828

What does it mean ?

ERROR_DS_COUNTING_AB_INDICES_FAILED  
The attempt to count the address book indices failed.
Value: 8428 | 0x20EC | 0b0010000011101100

Where does it come from ?

FACILITY_WIN32  
Provides a way to handle error codes from functions in the Win32 API as an HRESULT. (Error codes in 16 - bit OLE that duplicated Win32 error codes have also been changed to FACILITY_WIN32)
Value: 7 | 0x007 | 0b00000111

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