CSV Opens in One Column
The file delimiter does not match the program’s expected separator.
LIKELY CAUSE
Why it happens
Detect comma, semicolon or tab and import rather than double-clicking.
SAFE FIX
What to do
Use Excel Data → From Text/CSV or WorkTools delimiter detection.
Debug in this order
- Reproduce the problem on the smallest sample that still fails.
- Inspect the exact keys, types, ranges or markup involved instead of only the displayed value.
- Fix the root cause, then rerun the original case and one known-good case.
- Document the rule if the same problem can return in recurring work.
Do not hide an unexplained data error with a cosmetic workaround. Make the input and matching logic predictable first.