Error 0x80040091

Value: -2147221359 | 0x80040091 | 2147745937

What does it mean ?

IO_WARNING_SOFT_THRESHOLD_REACHED_EX  
Disk %2 has crossed a capacity utilization threshold and used %3 bytes. When the threshold was crossed, there were %4 bytes of remaining capacity.
Value: 145 | 0x0091 | 0b0000000010010001

Where does it come from ?

FACILITY_ITF  
COM/OLE Interface management. FACILITY_ITF is designated for user-defined error codes returned from interface methods
Value: 4 | 0x004 | 0b00000100

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