How to Resolve SQL Server Error 5172 – Fix SQL Server Header Error 5172
SQL Server stores its physical data in the primary database file, which contains the data by pages which store data. The header information of a .mdf file is stored by the first page, called a header page. This page contains the important information of this database file like file size, signature etc…. When a user attempts to attach the MDF / LDF database file stored on their system, a message box appears “The header for the “databasename.mdf” is not a valid database file header. The FILE SIZE property is incorrect. (SQL Server error 5172). It occurs when the header information of a .mdf file becomes corrupted.