Backtest Does Not Run
Published Jun 22, 2026 · Updated Oct 16, 2026
Backtests run in your browser: the page loads the backtest engine, downloads candles from the market source, runs on your device, and then saves the result to the server. A failure can come from the engine load, the settings, the market data, or the save. Go to Strategy → Strategy backtest.
What if it errors before or during the run?
| Message | Cause | Fix |
|---|---|---|
| Backtest engine failed to load | The browser could not load the backtest engine | Reload the page; disable extensions that may block scripts, or try another browser |
| This strategy is not supported by the current backtest engine. | This strategy cannot be backtested on the web | Pick a backtest-capable strategy |
| Complete the required strategy setting: … / Strategy config validation failed: … | A setting is missing or out of range | Fix the setting the message names |
| Backtest data planning failed | Settings are incomplete, so the data to download cannot be planned | Click Go to this setting, complete it, and run again |
| Invalid backtest range / Initial equity must be positive | The dates or initial equity are invalid | Adjust “Start date”, “End date (inclusive)”, or “Initial equity (USDT)“ |
| Market check failed: … does not support these USDT perpetual markets: … | The chosen market source lacks these markets | Click Switch to … for an available source, or Retry |
| Incomplete market data | Markets in the range are missing, have no candles, lack warmup candles, and so on | Switch the market source, adjust the range, or click Remove N unavailable markets |
| Backtest failed | Something went wrong during the run | Click Run again; if it fails again, note the exact message |
| Backtest canceled | The run was canceled and produced no result | Run it again |
Market-source notices:
- “Using Binance market data”: Gate market APIs do not allow browser cross-origin access, so Binance is used instead; you can also pick another source.
- “OKX market data”: OKX uses smaller candle pages, so seven days of 1-minute data can take tens of seconds longer; beyond roughly three months, funding history may be incomplete.
What if it is slow or the tab freezes?
- When you see “This range is data-heavy and may take several minutes when the strategy contains multiple markets.”, shorten the range, trade fewer markets, or use a coarser “Simulated backtest candle interval”.
- Higher parameter-sweep concurrency uses more CPU and memory. If the tab freezes, lower concurrency and try again.
- The backtest runs in the current tab, so don’t close or reload it while it runs.
What if the backtest finishes but fails to save?
Spot the save error
When a run finishes, the page saves that version to the server. If saving fails you see “Backtest finished, but saving to the server failed. You can retry.” The result then lives only in the current page.
Click Retry save
Click Retry save. Retrying does not create a duplicate version. Don’t close or reload the page until it saves, or this result is lost.
Parameter sweeps work the same way
If a finished sweep shows “Cloud save failed”, the local result stays viewable, and Retry save saves again under the same sweep ID.
Older versions marked “Curve not saved” keep their parameters and summary metrics. Apply the parameters and run again to see the full result.
What if the result looks wrong?
- Status “Completed with errors”: expand “Backtest errors” for the exact messages. If you see “Too many repeated order failures were merged…”, reduce simultaneous symbols, grid depth, or cell size, or raise initial equity.
- “Some markets are missing start candles” or “Some markets have a mid-range candle gap”: the run finished, but results for those markets are gap-affected, and mid-range gaps matter more.
- An empty trade list alone does not mean the run failed: positions may still be open. Check positions, orders, and data notices before changing the strategy.
Still stuck?
Send the experiment name or page URL, the version number, your settings (market source, symbols, start and end dates, simulated backtest candle interval, initial equity), the exact message, and your browser to support@alphafox.app.