Excel Workbook Error Cleanup

I’m working with a fairly large Excel workbook that has begun throwing multiple formula errors and showing signs of weak data validation. At the moment I’m not sure which specific functions are misbehaving, so I need an experienced eye to audit the sheets, trace the problem cells, and restore everything to a stable, accurate state.

The most urgent pain-points are:

• Formula errors scattered across several interconnected sheets (the standard #VALUE!, #REF!, or similar messages pop up in different places).
• Data validation that no longer stops incorrect data entries, allowing wrong codes and inconsistent formats to slip in.

You are free to use whichever method you trust—formula auditing tools, error-checking rules, VBA snippets for quicker tracing, Power Query for reshaping data—so long as the end result is a clean, reliable workbook.

Deliverables
• Revised workbook with all formulas producing correct results
• Re-implemented data validation rules that prevent incorrect entries
• A short change log highlighting what was fixed and why

Once those items are in place, I’ll run a quick test with my typical data to confirm we’re error-free. If we pass that check, the project is complete.