Error 0x00042809

Value: 272393 | 0x00042809 | 272393

What does it mean ?

VDS_S_DISK_DISMOUNT_FAILED  
Failed to dismount one or more of the volumes on the disk.
Value: 10249 | 0x2809 | 0b0010100000001001

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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