Synthetic example · not customer work

Sample diagnostic: cTrader indicator stops plotting after an update

This fictional incident demonstrates the structure of a bounded written diagnostic. It does not represent a client, a real proprietary indicator or a trading-performance result.

Finding

The indicator builds and loads; its index guard prevents every output assignment.

Smallest repair

Correct and document the warm-up boundary, then retest the same frozen cases.

Scope boundary

One failure is diagnosed; source repair is a separate fixed milestone.

1. Frozen evidence

Platform: cTrader Desktop 5.9 / Windows / synthetic environment
Artifact: One fictional authorized-source C# custom indicator
Last known working: cTrader Desktop 5.8 / clean instance
Current symptom: Build succeeds; indicator loads but plots no values
Build result: 0 errors, 0 warnings
Dependency boundary: No custom indicator, file, network or NuGet dependency
First divergence: Calculate executes, but every output remains NaN

2. Failure-stage matrix

Swipe the table sideways to read every stage.

Stage	Observed evidence	Conclusion
Build	Assembly compiles with 0 errors and 0 warnings	Not a compiler failure
Load	Indicator attaches in a clean instance without an exception	Not a loading failure
Calculate	Calculate is called, but source validation rejects every index	First reproducible divergence
Plot	Output series receives only NaN values	Downstream symptom, not root cause

3. Repair acceptance cases

First valid historical index writes a finite value.
Warm-up indices remain explicitly NaN without throwing.
The latest closed bar matches the frozen 5.8 reference value within the agreed tolerance.
A clean 5.9 instance builds, loads, calculates and plots with no hidden dependency.

Software-engineering example only. All versions, observations and values on this page are synthetic and are not trading advice.

Trading risk disclosure

Futures and forex trading contains substantial risk and is not for every investor. An investor could potentially lose all or more than the initial investment. Risk capital is money that can be lost without jeopardizing one's financial security or lifestyle. Only risk capital should be used for trading, and only those with sufficient risk capital should consider trading. Past performance is not necessarily indicative of future results.

Hypothetical performance disclosure

Hypothetical performance results have many inherent limitations. No representation is being made that any account will or is likely to achieve profits or losses similar to those shown. There are frequently sharp differences between hypothetical performance results and the actual results subsequently achieved by any particular trading program. Hypothetical results are generally prepared with the benefit of hindsight, do not involve financial risk, and cannot completely account for the impact of financial risk in actual trading. Market conditions, the ability to withstand losses, and adherence to a trading program can all materially affect actual results.

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