Budibase/budibase · error

Could not read CSV

Error message

Could not read CSV

What it means

During CSV streaming, readCsv sets csvError=true when the stream emits an error event (a malformed/invalid CSV row) and the promise's catch converts that into 'Could not read CSV' to hide the low-level parser error. It signals the CSV content itself could not be parsed, as opposed to transport failures which are rethrown unchanged.

Source

Thrown at packages/server/src/integrations/s3.ts:274

      throw new Error("Unable to retrieve CSV - invalid stream")
    }

    let csvError = false
    return new Promise((resolve, reject) => {
      fileStream.on("error", (err: Error) => {
        reject(err)
      })
      const response = csv()
        .fromStream(fileStream)
        .on("error", () => {
          csvError = true
        })
      fileStream.on("end", () => {
        resolve(response)
      })
    }).catch(err => {
      if (csvError) {
        throw new Error("Could not read CSV")
      } else {
        throw err
      }
    })
  }

  async delete(query: { bucket: string; delete: string }) {
    return await this.client.deleteObjects({
      Bucket: query.bucket,
      Delete: JSON.parse(query.delete),
    })
  }
}

export default {
  schema: SCHEMA,
  integration: S3Integration,
}

View on GitHub (pinned to a81a902e9a)

Solutions

1. Open the S3 object and validate the CSV: check headers, quoting, delimiter, and that it is not an HTML/JSON error page — re-export the file correctly.
2. Re-upload the file ensuring UTF-8 encoding and consistent quoting (e.g. export with standard CSV tooling).
3. If the delimiter is non-comma, configure the query's CSV parsing options accordingly.
4. Check the object is fully uploaded and not truncated (compare sizes/checksums).

Example fix

// before: CSV with inconsistent columns / stray quotes
name,age
"Alice,30
Bob,not,a,number
// after: well-formed CSV re-exported
name,age
Alice,30
Bob,42

// Pre-validate the object parses before ingesting
const lines = csvText.split("\n")
const cols = lines[0].split(",").length
if (lines.some(l => l.trim() && l.split(",").length !== cols)) {
  throw new Error("Malformed CSV: inconsistent column counts")
}

function isCsvParseFailure(err: unknown): err is Error {
  return err instanceof Error && err.message === "Could not read CSV"
}

try {
  const csv = await s3Integration.readCsv(query)
} catch (err) {
  if (err instanceof Error && err.message === "Could not read CSV") {
    // re-export/repair the source file, then retry
  } else { throw err }
}

When it happens

Trigger: The fileStream emits an 'error' event while piping rows (csvError flag set) — i.e. the parser rejects the CSV content mid-stream during an S3 read CSV query execution.

Common situations: Downloading a CSV with inconsistent column counts, wrong delimiter/quote characters, non-UTF8 encoding, or an HTML/JSON error page saved as .csv; truncated uploads; exporting tool produced malformed quoting that the CSV parser rejects.

Related errors

• Unable to retrieve CSV - invalid stream
• Unable to determine delimiter
• Unable to retrieve stream - invalid response
• Error constructing OIDC refresh strategy: message=${err.mess
• Access denied to object store bucket.${err}

AI-assisted analysis of Budibase/budibase@a81a902e9a (2026-08-29). Data as JSON: /api/errors/e16983677976f366. Report an issue: GitHub.