What causes Errors.HasError?

A column value in the source data is null, empty, or of an unexpected type that causes a transformation step to fail. A custom function or M expression wrapped in try returns an error due to invalid input data. Data source returns inconsistent schemas across rows, causing type conversion errors in specific records. Arithmetic or text operations applied to columns containing mixed or malformed values

How do I fix Errors.HasError?

Step 1: In Power Query Editor, add a custom column using try [YourColumn] to expose the HasError, Value, and Error record fields for each row. Step 2: Expand the resulting record column and filter rows where HasError equals true to isolate the problematic records. Step 3: Inspect the Error.Message and Error.Reason fields on failing rows to identify the root cause of each individual error. Step 4: Apply defensive transformations using try [expression] otherwise [defaultValue] to substitute safe fallback values for rows that error. Step 5: Address upstream data quality issues in the source system or add explicit type checks and null guards before the failing transformation step

Medium severitydata format

Power BI Refresh Error:
Errors.HasError

What does this error mean?

The HasError field in a Power Query try expression record is true, indicating that a wrapped expression failed to evaluate and produced an error instead of a valid value. This typically surfaces when using try...otherwise patterns or expanding error records in Power Query.

Common causes

1A column value in the source data is null, empty, or of an unexpected type that causes a transformation step to fail
2A custom function or M expression wrapped in try returns an error due to invalid input data
3Data source returns inconsistent schemas across rows, causing type conversion errors in specific records
4Arithmetic or text operations applied to columns containing mixed or malformed values

How to fix it

1Step 1: In Power Query Editor, add a custom column using try [YourColumn] to expose the HasError, Value, and Error record fields for each row
2Step 2: Expand the resulting record column and filter rows where HasError equals true to isolate the problematic records
3Step 3: Inspect the Error.Message and Error.Reason fields on failing rows to identify the root cause of each individual error
4Step 4: Apply defensive transformations using try [expression] otherwise [defaultValue] to substitute safe fallback values for rows that error
5Step 5: Address upstream data quality issues in the source system or add explicit type checks and null guards before the failing transformation step

Frequently asked questions

Will Power Query silently ignore errors if I use try...otherwise, and will my report still show data?

Yes — try...otherwise will replace erroring values with your specified fallback, so the refresh will succeed. However, affected rows will carry the fallback value rather than the true value, which can silently skew your metrics. Always monitor error row counts to understand the extent of data quality issues.

How do I see all errors across my entire query, not just one column?

In Power Query Editor, go to View > Query Diagnostics or use Keep Errors / Remove Errors transforms on individual steps. You can also add a custom column with try [Step] and expand it to enumerate all row-level errors for a given transformation step.