Metatrader 4 Terminal Sometimes Changes Account on Update. There is a Real Risk of Capital Loss.

 

I write this report in the hope that the MT4 update bugs are corrected, and users take additional precautions with their accounts.

I recently upgraded to Build 500, and I had a bad experience. First, you may have noticed that sometimes it can upgrade, and sometimes in can't, so it tries again the next time it's restarted, and hopefully it will succeed. This isn't so much of a problem, although it made me think at first that my system was failing to update, and so I lost time trying to fix it (and got somewhat frustrated in the process), only to find out that it just keeps trying until it succeeds.

Now, a bigger problem: After the update, it sometimes changes accounts without warning, and it doesn't disable experts! As a result of this, I have lost money on two accounts. It is frustrating in itself to lose money in FOREX, but is more so to lose money when it's not one's fault at all.

I advice traders to disable experts when closing terminals for updates, and do not allow them to take place if experts were not disabled first. Even removing the active experts from charts before updating is not an extreme measure, as MT4 can have quite unpredictable behavior when it updates; for example, in my experience it can distort some custom indicators, requiring an additional restart of the terminal to restore everything to normal. It would be best if you could make sure, whenever possible, that updates are applied on weekends, when the market is closed and there is no risk of opening trades.

In the more extreme of the two cases of money lost, I was just naively updating a terminal which operated on a demo account. What harm could come from that? I thought about removing the active expert advisor, as I was going to change it for another, but considered it unnecessary at that point. At first, the terminal didn't want to update, so I restarted it 3 times and the third succeeded. However, it then changed the demo account for the real account it had on file, did not disabled experts (something it must always do, as it is specified in the options), and distorted the custom indicator the expert was using. All of those things it did! So, having that bogus information, it simply opened a trade. It took me some long seconds to realize what the hell was happening. I closed the trade as soon as I could (after removing the expert, of course!), and not surprisingly some money was lost.

I hope many of you can prevent this problem.

 

 
It sounds to me like you had several terminals running out of the same directory. Last one closed changed accounts.
 
It is not possible to install several instances of Metatrader on the same directory (whenever you try to install on the same directory, the installer warns you and overwrites the previous installation). But in any case, all of my installations are in different directories.