How to fix Error 9987 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 9987 – Invalid NEAR Clause Max Gap Argument

Why This Error Happens

This error occurs when a Full-Text Search query uses the NEAR clause with a MAX_GAP or MAX parameter that does not conform to the expected syntax, typically caused by passing a non-integer value, a negative number, or a malformed string instead of a valid integer or the literal keyword MAX. This is almost always a query-authoring issue rather than a server configuration problem, often introduced by dynamically generated SQL, ORM-translated queries, or copy-pasted T-SQL with incorrect syntax. In rare cases, it can also surface after upgrading to SQL Server 2025 if legacy Full-Text Search queries relied on deprecated or non-standard NEAR syntax that is now strictly validated.

Step-by-Step Resolution Guide

Step 1: Identify the Offending Query

  • Capture the exact T-SQL statement that triggered Error 9987 using SQL Server Profiler, Extended Events, or the application log that reported the failure.
  • Look specifically for CONTAINS or CONTAINSTABLE predicates that use the NEAR keyword, for example:
    CONTAINS(column, 'NEAR((word1, word2), 5)')
  • Check if the second argument (the max gap value) is a variable, string, or user-input value rather than a hardcoded integer.

Step 2: Correct the NEAR Clause Syntax

  • Ensure the max gap argument is either a non-negative integer (e.g., 0, 5, 10) or the literal keyword MAX (case-insensitive), with no quotes around it.
  • Valid example: CONTAINS(column, 'NEAR((word1, word2), MAX)')
  • Valid example: CONTAINS(column, 'NEAR((word1, word2), 10)')
  • Invalid example to fix: CONTAINS(column, 'NEAR((word1, word2), "10")') — remove the quotes around the numeric value.
  • If the value is passed via a parameter or variable, add validation logic in the application layer to ensure only integers ≥ 0 or the string MAX are passed through.

Step 3: Update Application or ORM Query Generation Logic

  • If the query is generated dynamically (e.g., via Entity Framework, Hibernate, or a custom data access layer), inspect the code responsible for building the CONTAINS predicate string.
  • Add input sanitization to cast or validate the max gap value as an integer before concatenation:
    int maxGap = Math.Max(0, userInputValue);
  • Redeploy the updated application build or stored procedure to Windows Server 2025 / Windows 11 and restart the SQL Server service if the fix involves a compiled stored procedure:
    Restart-Service -Name 'MSSQLSERVER'

Step 4: Rebuild or Validate the Full-Text Index (If Needed)

  • If the error persists despite correct syntax, verify the Full-Text Catalog is not corrupted by running:
    ALTER FULLTEXT INDEX ON [YourTable] REBUILD;
  • Check the SQL Server error log located at C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Log\ERRORLOG for any related Full-Text Search engine warnings.

Alternative or Verification Steps

  • Re-run the corrected query directly in SQL Server Management Studio (SSMS) connected to your SQL Server 2025 instance and confirm it executes without raising Error 9987.
  • As an alternative, temporarily replace the NEAR clause with a simpler CONTAINS predicate (without proximity search) to confirm the base query logic works, then reintroduce NEAR incrementally to isolate the exact malformed argument.