Fix, debug or upgrade an existing MT4/MT5 Expert Advisor
Your developer disappeared, the EA stopped working after a broker change, or it trades differently live than it did in the backtest. Send me the source code and a description of the problem. You get an honest assessment and a fixed quote before any work starts.
Mutual NDA before you share your strategy · reply within one working day
- Order errors such as 130, 131 and 134 on MT4, or 10016 and 10030 on MT5 (invalid stops, invalid volume, unsupported filling mode)
- No trades on a new broker because of symbol suffixes, stops levels or filling modes
- Lost positions after a restart, or doubled exposure
- Live results far from the backtest because of look-ahead or a repainting indicator
- Runtime crashes: array out of range, zero divide, invalid handles
- Old MQL4 code that no longer compiles on current builds
- Starting price
- $80
- Typical delivery
- 1–5 days
- Revisions
- 2 revision rounds
- Handover
- Fixed source + change log
How a fix works.
- 01
Send the source and the symptoms
The .mq4 or .mq5 file, what you expected, what happened, and the Experts and Journal logs from the terminal if you have them.
- 02
Assessment and fixed quote
I find the cause, explain it in plain language, and quote a fixed price. Small fixes are often quoted the same day.
- 03
Fix and retest
The fix is tested on the scenario that failed and on a normal backtest, so nothing else changed by accident.
- 04
Delivery with a change log
You get the corrected source, the compiled file and a list of every change, in case you work with another developer later.
Not broken, just not finished?
Common upgrades to working EAs:
- Add a prop-firm guard: daily loss, maximum drawdown, news and lot caps
- Add a news filter, session filter or spread filter
- Add trailing stops, break-even or partial closes
- Add an on-chart control panel with live status
- Move the EA from MT4 to MT5
- Clean up and comment code that nobody can read any more
Symptoms, usual causes and fixes.
Most broken EAs fail in a handful of familiar ways. These are the ones I check first.
| Symptom | Usual cause | Fix |
|---|---|---|
| No trades at a new broker | Symbol suffix, stops level or filling mode not handled | Read the broker’s symbol settings at start-up; log rejected orders |
| Trades open twice | No check for an existing position after a restart or a timeout | Rebuild state from open positions; use magic numbers consistently |
| Stops placed in the wrong place | Points and pips confused on 5-digit or gold quotes | Calculate distances from the symbol’s tick size |
| Great backtest, poor live results | Logic reads the unfinished bar, or an indicator repaints | Move decisions to closed bars; replace or fix the indicator |
| EA stops after a weekend | Session or day logic built on local time, not server time | Use server time consistently, with daylight-saving handled |
| Terminal freezes or lags | Heavy calculations or indicator handles created on every tick | Create handles once; calculate only on new bars |
Common questions
I only have the .ex4 or .ex5 file. Can you fix it?
No. Compiled files cannot be edited, and decompiling is unreliable and usually breaks the seller’s licence. If you can describe what the EA does, or I can observe it on a demo account, I can rebuild it from scratch as a new project.
Will you change how my strategy trades?
Only to fix what is broken. Any change that affects trading behaviour is explained first and needs your approval, and every change is listed in the change log.
How much does a fix cost?
Small fixes start $80. Larger repairs and upgrades are quoted after I have read the code. You see the price before you pay anything.
How quickly can you look at it?
Usually within one working day. If your EA is live and misbehaving, say so in your first message and switch it off until it is fixed.
Tell me the strategy. I’ll tell you what it takes.
Fifteen minutes, no pitch. Mutual NDA before you describe anything you care about. You get an honest view of feasibility, timeline and price, even if the answer is “don’t build this”.