EA not working? The usual fixes
Nine times out of ten an EA that "does nothing" is a settings problem, not a broken file. Work down this list from the top — the first three fix most cases.
1. AutoTrading / Algo Trading is off
The toolbar button must be green. MT4 shows a sad face top-right on the chart when trading is disabled; MT5 shows a grey/red hat. Click the button, and also make sure the EA's own Allow live trading (MT4) / Allow Algo Trading (MT5) box was ticked when you attached it (right-click chart → Expert Advisors → Properties → Common).
2. The EA doesn't appear in the Navigator
- Wrong folder — EAs go in MQL4/Experts or MQL5/Experts, indicators in Indicators.
- Wrong terminal — an .ex4 never shows in MT5 and an .ex5 never shows in MT4. Check which you have.
- Not refreshed — right-click Navigator → Refresh, or restart the terminal.
3. Errors in the Experts tab
| Message | Meaning | Fix |
|---|---|---|
| invalid volume / invalid lots | Lot size below the broker minimum or wrong step | Set lot to 0.01 (or your broker's min) and check lot step |
| not enough money | Margin too low for that lot size | Reduce lots or increase demo balance |
| hedging is prohibited | MT5 netting account, EA opens opposite trades | Use a hedging account type |
| market is closed | Weekend or symbol session closed | Wait for market open |
| trade context is busy | Another EA/script is trading at that instant | Usually harmless; reduce number of EAs on one terminal |
| cannot load indicator "X" | The EA needs a custom indicator that isn't installed | Install the indicator file from the same post/archive into Indicators |
| trial expired / not licensed for this account | The file has an account or time lock | Nothing to fix on your side — try another version |
| DLL calls are not allowed | EA needs DLL imports | Tick "Allow DLL imports" only if you trust the file |
4. Right EA, wrong chart
- Symbol suffix. Broker symbols like
XAUUSD.morEURUSD.proconfuse EAs that hard-code "XAUUSD". Some have a suffix input; otherwise the EA won't find its symbol. - Timeframe. Many EAs only trade on the timeframe they were built for (M1/M5/M15/H1). Check the name and the post.
- Waiting for a signal. Trend and breakout EAs can legitimately sit for days. Give it a week on demo before declaring it dead.
5. Terminal-level causes
- Terminal not connected (bottom-right shows "No connection") — log in again.
- Very old build — update the terminal from the broker's download page.
- Read-only account / investor password login — you can't trade with an investor password.
- Options → Expert Advisors → "Allow automated trading" unticked (MT4: Tools → Options → Expert Advisors).
If it initialises cleanly, is on the right symbol/timeframe, and still never trades after a week, the file may simply be waiting on conditions or locked — pick another from the library and test it properly.
Frequently asked questions
Why does my EA show a sad face in MT4?
AutoTrading is disabled — either the toolbar AutoTrading button is off or "Allow live trading" was not ticked in the EA's properties (Common tab).
Why is my EA attached but not opening trades?
Most often AutoTrading is off, the lot size is invalid for the broker, the symbol has a suffix the EA doesn't recognise, or the strategy is simply waiting for a signal. Check the Experts tab for messages.
What does "hedging is prohibited" mean?
You are on an MT5 netting account and the EA tries to hold buy and sell positions at once. Open a hedging-type account instead.