How to fix Error 499 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 499 – Invalid Parameter for GETCHECKSUM Function

Why This Error Happens

Error 499 occurs when the CHECKSUM or BINARY_CHECKSUM function receives an argument it cannot process, typically an unsupported data type (such as text, ntext, image, XML, or CLR user-defined types) or a malformed expression passed as a column reference. This is commonly triggered during index maintenance, data comparison logic in application queries, or third-party ETL tools that pass entire rows—including LOB (Large Object) columns—into the checksum function without filtering unsupported types. It can also occur if a corrupted query plan or a legacy application (upgraded to run on SQL Server 2025) references deprecated data types that the new engine no longer implicitly converts.

Step-by-Step Resolution Guide

Step 1: Identify the Offending Query and Column

  • Check the SQL Server Error Log (C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Log\ERRORLOG) for the exact query text or object ID associated with Error 499.
  • Run the following diagnostic query to isolate LOB or incompatible columns in the table referenced by the error:
SELECT name, system_type_name 
FROM sys.dm_exec_describe_first_result_set(N'SELECT * FROM YourTable', NULL, 0);
  • Look specifically for columns typed as text, ntext, image, xml, geography, or geometry.

Step 2: Modify the Query to Exclude Unsupported Data Types

  • Rewrite the CHECKSUM(*) call to explicitly list only compatible columns rather than passing the whole row.
  • Example fix:
-- Instead of this:
SELECT CHECKSUM(*) FROM dbo.Orders;

-- Use this:
SELECT CHECKSUM(OrderID, CustomerID, OrderDate) FROM dbo.Orders;
  • If XML or LOB data must be included in the comparison, cast it explicitly to a supported type first, such as CAST(XMLColumn AS NVARCHAR(MAX)).

Step 3: Update Application/ETL Connection Strings and Drivers

  • Ensure the application or ETL tool (SSIS, Informatica, etc.) is using the latest ODBC Driver 18+ or OLE DB Driver for SQL Server, as older drivers may generate legacy CHECKSUM(*) calls incompatible with SQL Server 2025’s stricter type validation.
  • On Windows Server 2025/Windows 11, verify driver version via Control Panel > ODBC Data Sources (64-bit) > Drivers tab.
  • Update the driver using:
winget upgrade Microsoft.msodbcsql18

Step 4: Rebuild Corrupted Indexes or Statistics (If Applicable)

  • If the error surfaces during automated maintenance plans (e.g., checksum-based index integrity checks), rebuild the affected index to clear any residual corruption triggering the invalid parameter pass-through:
ALTER INDEX ALL ON dbo.Orders REBUILD;
  • Restart the SQL Server Agent service afterward via services.msc to ensure the job scheduler re-reads the corrected object metadata.

Alternative or Verification Steps

  • Re-run the original query or maintenance job that triggered Error 499; confirm the SQL Server Error Log shows no new instances of the error during the next execution cycle.
  • If the error persists despite column exclusion, use BINARY_CHECKSUM instead of CHECKSUM as a temporary workaround, as it has slightly different (though still limited) type-handling behavior, while you audit the full schema for incompatible data types.