Once upgraded the geth node to 1.6.1 it is not accepting queries anymore, throwing the following error:

Invalid argument 0: missing 0x prefix for hex data

That's weird for a query like this, where argument 0 seems to be a "from address" that starts with 0x.

eth_estimateGas([{ "from": "0x8c60d40a2e848251d139fc2b0b6b770bb3351ffd", "to": "0xe5f68950d479fab12797dabbe5a4b0d88ec7a722", "value": "1000000000000000000", "data": "0x4d61726b65745061792e696f202d204661756365743a2053656e642066756e647320746f203078653566363839353064343739666162313237393764616262653561346230643838656337613732322c2031206574686572" }])

Why this error? Why not in previous versions? Thx!

1 Answer 1


It seems new geth versions require every integer value must be in hex format. So,

"value": "1000000000000000000"

is wrong syntax. It should be:

"value": "0xde0b6b3a7640000"


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.