How to fix Error 9992 on Windows Server 2025 / Windows 11

by

Troubleshooting Guide: SQL Server Error 9992 – Full-Text Drop Batch Size Configuration Failure

Why This Error Happens

This error occurs when the SQL Server Full-Text Engine (MSFTESQL/FDHost process) is unable to read the registry or internal configuration value that defines the drop batch size for full-text indexing operations. This is typically caused by corrupted registry keys under the SQL Server instance hive, insufficient permissions for the SQL Server service account to access the configuration path, or incomplete/corrupted installation of the Full-Text Search component. In most cases, SQL Server will gracefully fall back to a default batch size, but the underlying configuration access issue should still be resolved to prevent cascading performance problems during index population.

Step-by-Step Resolution Guide

Step 1: Verify Full-Text Search Service Status

  • Open SQL Server Configuration Manager on Windows Server 2025 / Windows 11.
  • Navigate to SQL Server Services and confirm that SQL Full-text Filter Daemon Launcher is running for your instance.
  • If stopped, right-click and select Start, then set Startup Type to Automatic.

Step 2: Check Registry Permissions for the SQL Service Account

  • Open regedit and navigate to:
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL17.<InstanceName>\MSSearch
  • Right-click the key, select Permissions, and ensure the SQL Server service account (e.g., NT Service\MSSQLSERVER or your custom domain account) has Read and Query Value access.
  • Apply changes and restart the SQL Server service for them to take effect.

Step 3: Manually Set the Full-Text Drop Batch Size

  • Open SQL Server Management Studio (SSMS) and connect to the instance.
  • Run the following T-SQL command to explicitly configure the drop batch size at the instance level:
  EXEC sp_fulltext_service 'resource_usage', 3;
  • Restart the SQL Server and SQL Full-text Filter Daemon Launcher services via services.msc or Configuration Manager.

Step 4: Repair the Full-Text Search Component

  • Launch the SQL Server 2025 Setup wizard from the installation media or downloaded ISO.
  • Select Repair and choose the instance showing the error.
  • Allow the wizard to re-register Full-Text Search binaries and reset default configuration values.

Step 5: Review SQL Server Error Logs

  • Navigate to C:\Program Files\Microsoft SQL Server\MSSQL17.<InstanceName>\MSSQL\Log\ERRORLOG
  • Search for Event ID 9992 entries to confirm whether the fallback value is now stable across service restarts.

Alternative or Verification Steps

  • Run SELECT fulltextserviceproperty('ResourceUsage'); in SSMS to confirm the drop batch size value is correctly applied and no longer defaulting unexpectedly.
  • If the error persists after a repair, completely uninstall and reinstall the Full-Text and Semantic Extractions for Search feature via Add or Remove Programs > Microsoft SQL Server 2025 Setup, then re-run sp_fulltext_service to reconfigure settings from scratch.