Linq Update - Cannot perform runtime binding on a null reference

Question

I'm using LinqToExcel along with C# to read data from a MS Excel spreadsheet and then update data records in my MS SQL database.

The Excel file has these headers: COURSE_ID, PROVIDER_COURSE_TITLE

My code is like this:

public class TestDataCourse
{
    [ExcelColumn("PROVIDER_COURSE_TITLE")]
    public string cTitle
    {
        get;
        set;
    }
}

///////////////////////////////

string pathToExcelFile = @"C:\\O_COURSES.xlsx";
ConnexionExcel ConxObject = new ConnexionExcel(pathToExcelFile);

//read data from excel
var query1 = (from a in ConxObject.UrlConnexion.Worksheet<TestDataCourse>("O_COURSES")
                      select a).Take(2000).ToList();

//Get data from MS SQL database that need updated
var courses = _courseService.GetAllCoursesFromDB().Take(100).ToList();

int count = 0;

foreach (var course in courses)
{
     //Iterate through the excel doc and assign the 
     TestDataCourse fakeData = query1.Skip(count).Take(1).FirstOrDefault();

     course.CourseTitle = fakeData.cTitle;

     count++;
}

_courseService.Save();

When I run this code I can see that it does update some of the records in my database, but as the code execution continues, I get a Source Not Available tab open within my Visual Studio and a Cannot perform runtime binding on a null reference.

The null reference exception had me thinking that maybe there was some null data in the Excel doc, so I put this line of code into my for loop:

course.CourseTitle = fakeData == null ? "Course Test" : fakeData.cTitle;

But I still get the same problem.

Could anyone please help?

Thanks.