The Full-Text Search component is not completely rolled back to the Service Pack 1 version after you uninstall Cumulative Update 3 for SQL Server 2008 Service Pack 1 that is applied by using a slipstream installation
On a Microsoft Windows-based computer, you apply Cumulative Update 3 for SQL Server 2008 Service Pack 1 by using a slipstream installation.For more information about this cumulative update package, click the following article number to view the article in the Microsoft Knowledge Base:
971491 Cumulative update package 3 for SQL Server 2008 Service Pack 1
You try to uninstall this cumulative update after the slipstream installation.
In this scenario, the Full-Text Search component is not completely rolled back to the SQL Server 2008 Service Pack 1 version.
To confirm whether you are encountering this issue, you can check the SQL Server Full-Text Key file (Sql_fulltext_keyfile.dll) in the SQL Server 2008 Installation folder. Typically, this file is located in the following folder: