Error 0x8024001B

Value: -2145124325 | 0x8024001B | 2149842971

What does it mean ?

WU_E_SELFUPDATE_IN_PROGRESS  
The operation could not be performed because the Windows Update Agent is self-updating.
Value: 27 | 0x001B | 0b0000000000011011

Where does it come from ?

FACILITY_WINDOWSUPDATE  
Windows update
Value: 36 | 0x024 | 0b00100100

Other Errors for FACILITY_WINDOWSUPDATE