Specified cast is not valid

To resol ve thiserror find below the updates code

// Retrieve the value from session and cast it to int
int dupRecords = (int)(Session["dupRecords"] ?? 0);
int totRecords = (int)(Session["totRecords"] ?? 0);

// Increment the values
dupRecords++;
totRecords++;

// Store the updated values back in session
Session["dupRecords"] = dupRecords;
Session["totRecords"] = totRecords;

In the updated code, i cast the retrieved values from Session["dupRecords"] and Session["totRecords"] to int using (int)(Session["..."] ?? 0). The (int?) part is not required since we are explicitly assigning a default value of 0 using the null coalescing operator (??) if the session variable is null or does not exist.

After incrementing the values, we assign the updated values back to the session variables Session["dupRecords"] and Session["totRecords"].

By explicitly casting the values to int, you can perform arithmetic operations on them without encountering any errors.