Error 0x80042520

Value: -2147212000 | 0x80042520 | 2147755296

What does it mean ?

This operation is not allowed on online packs. The pack must be offline.
Value: 9504 | 0x2520 | 0b0010010100100000

Where does it come from ?

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

Other Errors for FACILITY_ITF