You plan to create a dataflow by using Power Query to transform the data. You observe that some cells display an error instead of the expected data. You need to obtain more details about the errors…

Selecting the entire row highlights all values in that row but does not surface the structured error details for the specific errored cell.

Flow Checker is a Power Automate tool that validates the structure and connections of a cloud flow - it has no role in Power Query dataflow diagnostics.

When you select a cell containing an error in Power Query's data preview, the editor displays the complete error record - including the error reason, message, and detail fields - in the lower preview area, giving specific information needed to diagnose and fix the transformation issue.

App Checker is a Power Apps tool that identifies issues in a canvas or model-driven app and is unrelated to Power Query dataflow errors.

The Advanced Editor displays the raw M query code for the current step, which shows the transformation logic but does not expose runtime error details for individual cell values.