How to fix Error 5345 on Windows Server 2025 / Windows 11

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Why This Error Happens

Error 5345 occurs when you define an inline schema using the WITH clause in an OPENROWSET(BULK...) statement and specify only OFFSET or only LENGTH for a column, instead of both. SQL Server 2025’s bulk schema parser requires both the starting byte position (OFFSET) and the exact byte count (LENGTH) to correctly map fixed-width or binary data into a column definition. Without both values, the engine cannot determine the field boundaries, so it rejects the query at parse/compile time rather than risk a silent data-misalignment during the read operation.

Step-by-Step Resolution Guide

Step 1: Review the Inline Schema Definition

  • Open the T-SQL script containing the OPENROWSET(BULK...) WITH (...) clause.
  • Locate every column definition that uses OFFSET or LENGTH as part of fixed-width field parsing.
  • Confirm whether both keywords are present for each column — partial definitions (only one of the two) are the direct trigger for Error 5345.

Step 2: Correct the Column Definitions

  • Edit the schema so each affected column explicitly declares both parameters, for example:
SELECT *
FROM OPENROWSET(
    BULK 'C:\Data\legacyfile.dat',
    SINGLE_BLOB
) AS x
CROSS APPLY OPENJSON(x.BulkColumn)
WITH (
    EmployeeID   INT      '$.id'      OFFSET 0  LENGTH 4,
    EmployeeName VARCHAR(50) '$.name' OFFSET 4  LENGTH 50
);
  • Ensure the OFFSET value reflects the correct starting byte in the source file/stream and the LENGTH value matches the exact byte-width expected for that field.
  • Save the corrected script in your project directory, e.g., C:\Scripts\SQL2025\FixOpenRowsetSchema.sql.

Step 3: Validate Syntax in SQL Server Management Studio (SSMS)

  • Open SSMS (connected to your SQL Server 2025 instance on Windows Server 2025 or Windows 11).
  • Paste the corrected query and use Query > Parse (Ctrl+F5) to confirm there are no syntax errors before executing.
  • Execute the query and confirm Error 5345 no longer appears in the Messages tab.

Step 4: Check for Legacy or Copy-Pasted Scripts

  • Search your solution or deployment scripts folder (e.g., C:\DeploymentScripts\) for other instances of OPENROWSET or OPENJSON with inline WITH schemas.
  • Apply the same OFFSET/LENGTH pairing fix to any additional occurrences to prevent the error from resurfacing in other stored procedures or ETL jobs.

Alternative or Verification Steps

  • Re-run the corrected query and confirm the result set returns properly parsed columns without truncation or misaligned data — this verifies both the fix and correct byte mapping.
  • As an alternative, if you don’t need fixed-width binary parsing, remove OFFSET/LENGTH entirely and let SQL Server infer schema automatically via OPENJSON default parsing (WITH clause using only JSON path, without byte offsets).