Error 0x80242019

Value: -2145116135 | 0x80242019 | 2149851161

What does it mean ?

WU_E_UH_CUSTOMINSTALLER_INVALID_SIGNATURE   
The custom installer signature did not match the signature required by the update.
Value: 8217 | 0x2019 | 0b0010000000011001

Where does it come from ?

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

StackOverflow

Other Errors for FACILITY_WINDOWSUPDATE