Troubleshooting
Quick fixes for the errors beginners hit most often. Each entry shows the message, what it means, and what to try next.
Grouping errors
Section titled “Grouping errors”Separator mismatch
Section titled “Separator mismatch”--group "<g>" and --group-pattern "<p>" separators do not match (expected "<from g>", got "<from p>")-g and -p must declare the same separators between dimension slots. A comma-separated -g region,product,category needs a comma-separated -p x,y,z, not x/y/z.
Fix: Make -p mirror -g — same separator characters in the same positions. See Matching separators.
Dimension count mismatch
Section titled “Dimension count mismatch”--group and --group-pattern dimension count do not match: N column(s) in "<g>", M slot(s) in --group-pattern "<p>"-g selects N columns but -p defines a different number of top-level slots. Common with bracket patterns where one column splits into multiple dimensions.
Fix: Count top-level slots in -p (each [...] bracket counts as one slot). They must match the number of -g columns. See Bracket slots.
Missing group column
Section titled “Missing group column”group column 'X' not found; available: [...]The column name in -g does not match a CSV header or JSON field exactly (case-sensitive).
Fix: Check spelling and run vizb data.csv -o out.html without -g first to confirm headers. See Grouping CSV/JSON data.
Pattern needs x or y
Section titled “Pattern needs x or y”pattern must contain xAxis (x) or yAxis (y)-p only assigned a name (n) or z dimension. At least one of x or y is required for grouping to take effect.
Fix: Add x or y to the pattern, e.g. -p n/x/y instead of -p n. See The Dimensions.
z requires x and y
Section titled “z requires x and y”zAxis (z) requires both xAxis (x) and yAxis (y)A z segment in -p or --group-regex needs both x and y to be present. z alone is not enough.
Fix: Include both x and y before adding z, e.g. -p n/x/y/z. See 3D Charts.
Regex missing x or y
Section titled “Regex missing x or y”regex '...' does not contain x (xAxis) or y (yAxis)Same rule as pattern syntax — the named capture groups must include (?<x>...) or (?<y>...).
Fix: Add (?<x>...) or (?<y>...) to the regex. See Regex Syntax.
Data errors
Section titled “Data errors”No numeric columns (CSV)
Section titled “No numeric columns (CSV)”no numeric columns found in CSVEvery column is non-numeric, or the file has no data rows after the header.
Fix: Ensure at least one column contains numbers. Text-only columns can be used with -g for dimensions but cannot be charted as series. See Tabular Data.
No numeric fields (JSON)
Section titled “No numeric fields (JSON)”no numeric fields found in JSONThe JSON objects have no numeric keys (after flattening nested objects to dotted keys).
Fix: Include at least one numeric field per object. See Tabular Data.
Parser errors
Section titled “Parser errors”Unknown parser
Section titled “Unknown parser”unknown parser 'X'; available: auto, [...]-P / --parser was set to a key vizb does not recognize.
Fix: Omit -P and let vizb auto-detect, or pick a valid key from the list in the error. See Parser Guide.