we deployed (via remix) the code below where one contract can influence a state variable in the other. For some reason if I deploy the contracts on Ropsten it doesn't work and if I deploy them on Kovan, this works just fine. Anyone any idea?

pragma solidity ^0.4.13;

contract A {

    uint public counter ; 
    function increment(uint add) {
       counter = counter + add;

contract B {

    function delegateIncrement(uint add) {
        A("here the address for contract A").increment(add) ; 
  • I get the error running out of gas, I even upped the gaslimit significantly, but that didn't work. Why is it running out of gas in Ropsten and not Kovan? Sep 22, 2017 at 19:13
  • Since you mention that you are deploying via Remix: Any chance that you forgot to recompile B with the new address of A, as deployed on Ropsten? "Out of gas" is what you see in some interfaces for an invalid opcode, which seems more likely than a failure to send enough gas.
    – carver
    Sep 22, 2017 at 20:08

1 Answer 1


If you're having trouble deploying the contract, it's probably because Ropsten blocks are very full right now. Try using a gas price greater than 56 gwei.

Kovan is also running on Homestead, while Ropsten is on Byzantium. I don't know why that would make a difference though.

  • What do you mean by "blocks are very full?" Sep 21, 2017 at 1:08
  • Deployingnis nog problem. It is the interaction that doesn't work in ropsten. If I use the function in contract A, the counter works fine. If I use the function in contract B, the counter doesn't chage value. I don't run into this problem on Kovan.... Sep 21, 2017 at 14:37

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