Access Violation write to 0x000.... Error

[yasasp]

Hello Dingmaotu,

I am stating to getting more and more "Access Violation write to 0x000...." Error while testing the bridge between MT4 and Python.

i am on x64 bit window 10. Can you please advise a solution?

[dingmaotu]

Could you post relevant code here? I need to know what kind of ZMQ topology you are using and the format of your message.

[yasasp]

Thanks for your time. Below is the message message format in MT4 and relevent function,

     pos="flat";
     if (OrderType() == OP_BUY) pos="long";
     if (OrderType() == OP_SELL) pos="short";
     InformPullClient(pSocket, StringFormat("%s|%f|%f|%f|%f|%f|%f|%f|%f|%f|%f|%f|%f|%f|%f|%f", pos,Bid, Ask, TotalOpenOrders(), MyPoint(),_Digits,OrderProfit(),OrderOpenPrice(),OrderStopLoss(),OrderTakeProfit(),iadxp,iadxn,iadxm,Max_Epsolon,Min_Epsolon,Epsolon_Dec));

// Inform Client void InformPullClient(Socket &pSocket, string message) {

ZmqMsg pushReply(StringFormat("%s", message)); pSocket.send(pushReply,true); // NON-BLOCKING }

[dingmaotu]

OK, how do you get the error? under what condition? Do you encounter error the first time the code is run? Please give me details so I can help.

[yasasp]

I tried to find the correlation of the error. But it appeared to be so random. It happen both in strategy tester and live mode. some times it comes with in 2~5 minutes and some times after ten minutes.

[dingmaotu]

I think you are passing invalid values (like pointers) to zmq lib functions. But I can not pin down the exact function based on current information. Have you tried to run the EA in Debug mode and check the exact line that caused this error?

[fcbeta]

Hello, I have a much more trivial problem with libzmq.dll, it does not load! Mt4 and window 7 enterprise x64. Naturally I checked your installation instructions. Thanks

[dingmaotu]

@fcbeta hi, you need to ensure that: 1. VC2015 runtime is installed; 2. 32bit DLL is used; 3. You need to enable DLL import in your EA or global configuration.

[fcbeta]

Hi @dingmaotu, unfortunately, the installation is correct: from downloaded folder \mql-zmq-master\Library\MT4\ to: MQL4\Libraries\libzmq.dll to: MQL4\Libraries\libsodium.dll from downloaded folder \mql-zmq-master\Include\ to: MQL4\ Include\Mql to: MQL4\ Include \Zmq finally the Script folder. I have also removed the old version VC2008 and installed the runtime VC2015

I tried on Windows XP sp3 with the same result, but with an old libzmq 2.0.10 library it works. There must be some other addiction I do not have?

[yasasp]

as its weekend, cannot run the live EA with debug mode. Instead, I printing all the parameters passing on tester. See below. Most of the time error generated at in the same location in a randomly. i do not see any invalid value.

I am planning to do the debug mode when the market is open.

[dingmaotu]

@fcbeta you are installing 64bit vc runtime.

[dingmaotu]

@yasasp I am not saying the input parameters. The parameters passed to native zmq functions might be incorrect. I am waiting for your debug results.

[fcbeta]

@dingmaotu, I had already installed the vc2015x64 as written, but I solved by installing also the vc2015x86 runtime. Thank you for your support. Fabio

[dingmaotu]

@fcbeta You are welcome.

[yasasp]

@dingmaotu, Those values printed on the above screen-shot are the values passes to ZMQ functions. Print functions were place just before calling the ZMQ function call...