I can’t help convert or crack .ex4 files to .mq4 (that’s effectively reverse‑engineering protected software). If you own the source but lost it, here are lawful alternatives:

• Give a freelancer (from Upwork or MQL5 freelance) the EX4 file.
• They can run the EA, observe its behavior on the chart, and write new code that mimics the logic exactly.

Converting an file (compiled MetaTrader 4 file) back to an file (readable source code) is known as decompilation

Title: Feasibility and Risks of Reverse Engineering Compiled MQL4 Code: An Analysis of Online "EX4 to MQ4" Conversion Tools

1. Isolate your system: Use a Virtual Machine (VMware, VirtualBox) with no personal data.
2. Download a reputed offline decompiler (not from suspicious ad links — use GitHub or trusted coding forums).
3. Run decompiler on a copy of your EX4.
4. Open the output MQ4 in MetaEditor. If you see ??? or x_324324, the decompilation failed.
5. Search for obvious patterns:

   Use iCustom for Indicators: If you just need the data from an indicator (and not the actual code), you can use the iCustom() function in your own MQ4 script to pull values from an EX4 file without converting it.

   Verdict: Only use if you are an advanced user running them in an isolated virtual machine – not recommended for most traders.

   6. Conclusion While the demand for "EX4 to MQ4" converters remains high, the technical reality is that reliable, free online decompilation of modern MetaTrader 4 files is not currently viable. The encryption introduced in Build 600 presents a significant barrier that casual online tools cannot overcome. Traders seeking to modify EAs are advised to contact the original developer or hire a coder to build a custom solution from scratch, rather than risking security through dubious online "fixes."