> ## Documentation Index
> Fetch the complete documentation index at: https://runway-docs.cfo.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Errors & troubleshooting

> Diagnose common Runway errors and learn where to go next.

Use this reference when a formula cell, database refresh, or modeled value does not behave as expected. Start with the visible label or symptom, then check the likely cause and fix.

## Formula errors

| Error label | What it means                                                                                                                                           | Example                                                                   | How to fix                                                                                                                             |
| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| `TYPE`      | The tooltip says: "This driver, or one of its formula inputs, is performing an operation across incompatible types or resolves to a non numeric value." | A Number driver uses `dateAdd()` and returns a date.                      | Change the driver to a Date driver, or change the formula so it returns a number.                                                      |
| `CIRC`      | The driver depends on itself in the same period, directly or through another formula.                                                                   | Revenue references Total revenue, while Total revenue references Revenue. | Remove the self-referential dependency. If the logic should use a prior period, reference the prior period instead of the current one. |

## Blank or unexpected values

### Null vs. zero

Runway treats `NULL` and `0` differently. `0` is an explicit value. `NULL` means no value was returned. Features such as **Most recent value** can pull forward the last known non-null value, but they do not replace an explicit zero.

For more examples, see [Propagating sparse data](/guides/modeling/propagating-sparse-data).

### Date-range misalignment

If a formula returns values in some months but not others, check the time range on the referenced driver or database field. A filter can exclude the month you are evaluating, and an integration-derived value may only exist in months where the source system returned data.

### Actuals vs. forecast boundary

Actuals formulas apply through [last close](/concepts/last-close). Forecast formulas apply after last close. If a value changes when you move last close, check whether the actuals formula, forecast formula, or a hardcoded value is winning for that month.

## Data refresh issues

### Data source health

Each data source's actions menu shows its refresh health. **Healthy** appears with the last-sync time. **Disconnected** or **Log in to resume updates** means Runway cannot refresh that source until the connection is restored.

### Circular dependency blocks refresh

Some database refreshes can be blocked by a dependency cycle between databases. The alert title is **Circular dependency blocks refresh**, with summary **These databases depend on one another, so Runway cannot refresh them automatically.**

The alert can show a **LOOP** section with the cycle path joined by **→**, plus **DETAILS** such as **depends on**, **Through**, and **Fields**. Break the cycle by changing the database formulas or configuration so one database no longer depends on another database that depends back on it.

## Getting help

If you are still blocked, email [support@runway.com](mailto:support@runway.com) with the error label, the driver or database name, the scenario you are in, and the formula or data source you were editing.

## What's next

* [Formulas basics](/concepts/formulas/formulas-basics)
* [Functions & operators](/concepts/formulas/functions-operators)
* [Last close](/concepts/last-close)