modified the flash update sketch to web update SPIFFS but I'm getting the following error. Although Update sketch works fine for firmware flashing

change

if(!Update.begin(maxSketchSpace, 100)){
Update.printError(Serial);
}

Serial Log / ERROR

Update: firmware.spiffs.bin
sleep disable
ERROR[10]: Magic byte is wrong, not 0xE9
bcn 0
del if1
usl

generating the SPIFFS file using the jar tool ( latest version )

Kindly guide!