Hi, I’m Jay Koo.
I didn’t start out planning to write about Excel. A few years back I was on a small operations team, and every Friday afternoon somehow turned into the same ritual — pulling numbers from three different spreadsheets, fixing broken VLOOKUPs, and figuring out why a report that worked fine last week suddenly returned a wall of #N/A errors. Nobody taught this stuff properly. You just broke things, googled the error, and slowly built up a mental list of fixes.
ExcelTroubleshoot is that list, written down.
This isn’t a place for abstract theory or textbook definitions. Every post here comes from a real problem — the kind that shows up mid-workday and needs an actual answer, not a lecture. A few things you’ll find:
- Common breakages — lookups that fail for no visible reason, dates that won’t calculate, duplicates that Remove Duplicates somehow misses
- Formulas that save time — XLOOKUP, FILTER, LET, LAMBDA, used the way people actually need them, not just documented
- Bigger builds — dashboards, VBA automation, and workflows for when you’re past quick fixes and want something that runs itself
If you’ve ever stared at a spreadsheet wondering why something that looks right keeps returning the wrong answer, you’re in the right place. That’s basically the whole premise of this blog.
Questions, corrections, or a problem you’d like covered — reach out through the Contact page.