Dependency Auditor allows you to trace error values in workbook. It shows how error values affects other cells. Also you can see how this error value is produced, i.e. which cell or calculation step produced error.

Dependency Auditor window has 2 options: Highlight errors and Filter highlighted cells. First option will highlight all cells, which contains error values. This will allow you to see which cells were affected by error. Second option will hide nodes, which doesn't have errors. This is useful to find beginning of error chain quickly.

Note These options could be used with Trace dependents command too. This will show you, how error in one cell affects to other cells.

This is highlighted errors:
Hightlight errors