EPPlus: "Column out of range" error with LoadFromCollection

Add Properties like { get; set;} for each variable, because the way epplus works is on properties of class.

For example, instead of using:

class student
{
    int num;
   string name;
}

use this:

class student
{
     int num { get; set; }
     string name { get; set; }
}

This is a bug in EPPlus library and it has been reported on September 25, 2017.