SqlCeError Class

try
{
    SqlCeReplication repl = new SqlCeReplication();

    // Fill repl properites here
    // ...

    // SqlCeReplication may throw SqlCeException which contains a 
    // collection of errors; SQL Mobile database engine always
    // returns one error in the collection
    //
    repl.Synchronize();
}
catch (SqlCeException e)
{
    foreach (SqlCeError error in e.Errors)
    {
        // Use SqlCeError properties if you need specific
        // application logic depending on the error condition
        //
        if (28577 == error.NativeError /*SSCE_M_SCHEMAHASCHANGED*/)
        {
            // Error specific logic goes here...
            //
        }

        // Note: For native error numbers, refer to SQL Server Mobile Errors
        // in the SQL Server Mobile Books Online
        //
        MessageBox.Show(error.Message);
    }
}