External table is not in the expected format

I have around 10 excel file in a directory and based on the date I am trying to sort and compare 2 files at a time using foreach loop using C# console application in Visual Studio 2019.

Below is the code:

string path = Directory.GetCurrentDirectory();
string finalFile = path + FileName;
string connString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + finalFile + ";Extended Properties=\"Excel 12.0 Xml;HDR=YES;\"";
OleDbConnection conn = new OleDbConnection(connString);
if (conn.State == ConnectionState.Closed)
conn.Open();
DataTable dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
foreach (DataRow roww in dtEmployeeDetails.Rows)
{
string query = "text query";
OleDbCommand cmd = new OleDbCommand(query, conn);
int dr = cmd.ExecuteNonQuery();
}
conn.Close();
conn.Dispose();

I am sometime successfully able to execute the code, but sometime i get the error as "External table is not in the expected format".