MT4 Build 600: Full Recap 5

Hi Eveyone,
today I’d like to give a recap about how to manage the new MT4 Build 600. I’ll briefly discuss the following points:

  1. Why Build 600 was released in the first place
  2. Key things to know about Build 600
  3. Why we still suggest to work with Build 509
  4. 1st way to avoid the update to Build 600: User Account Control
  5. 2nd way to avoid the update to Build 600: WebInstall removal
  6. How to revert to Build 509
  7. PimpMyEA’s plans for eventually migrating to Build 600

Let’s start with the first point:

1) Why Build 600 was released in the first place

MetaQuotes (the company that developed MetaTrader 4) has been working hard in the tast 2-3 years for developing its next generation trading platform (MetaTrader 5) in an attempt to keep the pace with more advanced and sophisticated trading platforms available among several brokers. However MT5 is pretty different from MT4 and very few traders have opted for this new platform.

Now MetaQuotes is trying to capitalize all the efforts spent on the development of MT5 by releasing a new Build version of MT4 that incorporates many features of MT5. The problem is that the majority of traders didn’t ask and were not prepared for this major update, hence the great deal of discussions and complaints you’ve probably read on many forums in the last couple of weeks.

Contrary to what I personally believed in the beginning, lots of brokers seem already prone to migrate to this new Build 600 without a whole lot of feedback from their customers. That’s why we must be prepared to understand and manage this new Build 600 (the very reason why I’m writing this post).

2) Key things to know about Build 600

Here are the 3 main aspects to keep in mind:

  1. The “MetaEditor” IDE (Integrated Development Environment) is different (new methods in the API, new reserved keywords, etc.), therefore source code compiled on Build 600 will not work on Build 509.
  2. Executable files (ex4) compiled under Build 509 will work on Build 600 too, with a few exceptions. If you incur compatibility issues the only options are: compiling again the source code under Build 600 OR reverting back to Build 509.
  3. The main folder where Experts Advisors, Indicators, Scripts are contained has changed: it is now outside the main MT4 installation directory. This folder is called “MQL4″ and you can access it through the new “File > Open Data Folder” menu which is available on Build 600. You can read this post for an example about copying files into this new “Data Folder”: Renko On Build 600 Solution!

3) Why we still suggest to work with Build 509

Firstly the new Build 600 is not yet as stable as the 509: MetaQuotes already sent out the Build 604 and it will probably keep rolling out new Builds in a short period of time until they finally end up with a stable Build that fixes most of the errors reported by end users and MQL4 developers.

Secondly you’ll probably realize that a subset of your current Expert Advisors and Custom Indicators do not work anymore on Build 600, so you should wait some times before you can finally get your hands on new ex4 files that were compiled under Build 600. If you just don’t want to waste time while a myriad of minor incompatibility issues get fixed by MQL4 developers worldwide, then stay with Build 509 for now.

4) 1st way to avoid the update to Build 600: User Account Control

If your operating system is Windows Vista or higher (Windows 7, Windows 8),  you should enable the “User Account Control” (just google it if you don’t know how to turn on this option). Doing so the automatic update to Build 600 should be blocked by the operating system until you explicitly authorize it. As an example if you run Windows 7 like I do, then you should see the following window popping up when MT4 tries to update to Build 600 or higher:


Fore more information please read this post: Don’t Update To MT4 Build 600, Yet!

Unfortunately some traders reported that in spite of the “User Account Control” being turned on their platform was automatically updated to Build 600. That’s why we also suggest to implement the workaround explained below.

5) 2nd way to avoid the update to Build 600: WebInstall removal

MetaTrader 4 stores pending updates in a folder like:


You may not be able to immediately locate this folder because it is hidden, in this case you can try using the Search feature on the entire C: drive in order to find it. Once you find it, you should delete the entire “WebInstall” folder. This will prevent MT4 from performing an update the next time you restart it. However this will only work 1 time, because MT4 will download again the update file and create the “WebInstall” folder while the platform is running. That means you should periodically delete this folder, especially right after you close all your MT4 platforms for the week-end.

6) How to revert to Build 509

If you still have at least 1 platform that runs Build 509, then you should backup it in a zip file. You can use this backup for setting up any number of MT4 Build 509 for all the brokers you are interested in.

Unzip the backup in the directory you prefer (preferably outside “C:\Program Files\”), then copy into it all the EAs and Custom Indicators you need, and also the .srv files in the “config” folder that contain the IP addresses of the broker’s servers you are interested in (e.g. “”, “”, etc.).

Finally double click the “terminal.exe” file. The first time you do that you’ll be asked “Login”, “Password”, and “Server” (remember to check the flag “Save account information”). You are running now again a MT4 Build 509 😉

7) PimpMyEA’s plans for eventually migrating to Build 600

Firstly we are checking all our executable files (that were generated under Build 509) and testing them under Build 600, so that we can provide a list of products that work just fine on Build 600.

Secondly we are compiling under Build 600 all products that show compatibility issues with the new Build.

Over time, we’ll provide versions compiled under the new Build for all products.


Your feedback on this post is very much appreciated :-)


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5 thoughts on “MT4 Build 600: Full Recap

  • Todd

    Thanks for helping us to understand what is going on with build 600.
    I know it caught me off guard. But so far after I downloaded new platform and fresh programs it has not hickupped yet.
    Thanks for such a quick file so I can run Heart EA.
    Pip On

  • Tom

    So much text unnecessarily. It does not work – in any case, not on a machine that is already infected by the MT4 600 Update.
    MF Vladimir attacks not only active platforms, but also those that are offline.

    • Paolo Post author

      Hi Tom, in your case you should implement step (6). Send us an email if you are not able to do that and we’ll assist you.
      Anyway, the update cannot be performed on offline platforms in you implement step (5).

  • Tom

    Hi, thanks for your reply

    1. I find on my Vista64 ‘WebInstall’ file only under OS (C :) / Users / myname / AppData / Roaming / MetaQuotes / Terminal and WebInstall / -and Folder WebInstall is empty
    2. When I start MT4 509 from a backup file (terminal.ex4), I see it in a few seconds and then 509 Platform disappears after 10-15 seconds reappeared, but now as 600 +
    3. It is obvious that there is a program activated and switches 509 to 600 +
    4. When I wanted to see 509 Online platform (1.5Y that has no active acc happened the same: platform disappeared for a few seconds and that happiness – appeared as a 600 + …