An exception of type 'System.OutOfMemoryException' occurred in mscorlib.dll but was not handled in user code asp.net

I'm having trouble getting this error resolved. My purpose is to collect data from an Excel file storing it in C # variables, which in turn will be inserted in SQL Server 2012. Reading is done line by line. Here is the code where the error happens:

Excel.Application excelApp = new Excel.Application();
Excel.Workbook WB = null;
Excel.Worksheet WS = null;
excelApp.Visible = false;


Convert.ToString(FileUpload1.PostedFile.FileName);
Response.Write(FileUpload1.PostedFile.FileName);



string excelpath = FileUpload1.PostedFile.FileName;
Convert.ToString(excelpath);

string workbookPath = excelpath;

WB = excelApp.Workbooks.Open(workbookPath, 0, false, 5, "", "", false, Excel.XlPlatform.xlWindows, "", true, false, 0, true, false, false);
WS = excelApp.Worksheets.get_Item("" + TextBox2.Text); 


String connectionString =
   "Data Source=localhost;" +
   "Initial Catalog=Teste;" +
   "User id=sa;" +
   "Password=123;";

Excel.Range last = WS.Cells.SpecialCells(Excel.XlCellType.xlCellTypeLastCell);
Excel.Range range = WS.get_Range("A1", last);
object ranger = range.Value;

Error:

  

An exception of type 'System.OutOfMemoryException' occurred in mscorlib.dll but was not handled in user code asp.net