Decompile EX4 to MQL4. What is a decompiled MQL4 indicator?
A decompiled (stolen) indicator is an indicator that was originally shared or sold as a protected EX4 file but hacked using an EX4-to-MQL4 decompiler to reveal it's source code (contents).

Why are EX4 files hacked or decompiled?

In a perfect world, EX4 files are innocently decompiled by users who had purchased an indicator from a coder but the coder was no longer available for support, and the user decided to "open" the file to improve or add to the indicator with good intentions.

Unfortunately, this is hardly the reason why protected EX4 files are hacked. The primary reason why decompiled files exist is because of scamming and theft. People who do not know how to code will take an EX4 file that was made by a coder and will decompile the file, re-name it to something different (usually something cheesy like "Pip Magic" etc.) then market it as their own.

How do I recognize if an indicator is decompiled?

The easiest way to spot a decompiled code is:

• Open the indicator in your MT4 editor
• If the code contains letters and numbers separated by underscores ie. gi_212 etc, it's decompiled

Also, many decompiled indicators have a watermark left at the top of the code stating it's decompiled by a EX4-to-MQ4 decompiler. A common example of this watermark:

• "Generated by ex4-to-mq4 decompiler FREEWARE 4.0.509.5"

Below is an example of a decompiled version of Ultra Trend Loss of information after decompiling

It is true, decompiling an EX4 file produces an editable MQL4 source code but in the process of decompiling, variable names are stripped and replaced with "machine" names.

MQL4 coders and programmers who code at a proficient level will name variables according to their purpose. If a variable is an Average, a coder might name this avgPeriod. A decompiler will rename this variable using a "machine" name such as g_393 or similar (just like the examples shown in the screenshot above).

Why does Forex-station refuse to edit or work on decompiled files?

Forex-station staff have a firm stance against decompiled MQL4 files simply because it's unethical and it's stealing.
If a coder has decided to protect their work, we must respect that.
It's the same reason why people lock the doors of their home when they are out. To prevent theft.

I downloaded an EX4 to MQL4 decompiler but it won't work with the EX4 file I have?

Newer MT4 builds do not allow EX4's to be decompiled.
This has been explained by Mladen here.

I want to learn how an indicator was coded, can I decompile it?

No. There are many indicators available at Forex-station that have been posted as MQL4 (source code) files already. New programmers can use these files as a reference and learn with what is freely available already.

Once you begin learning the ins and outs of coding and spending days on perfecting your own indicator, only then will you understand why others choose to "lock" their source codes and only release EX4 files.