ConnectionString property has not been initialized IIS - asp.net-mvc

Question

Having some issues when I deploy my application to IIS. This is only happening on two pages and the rest of my site works just fine when hitting the database.
public static List<Parent> GetParentsWithAssignedStudentsByISDId()
{
SqlConnection sqlConn = null;
SqlDataReader sqlDataReader = null;
string sConnString = ConfigurationManager.AppSettings["SMARTDBConn"];
var parents = new List<Parent>();
try
{
sqlConn = new SqlConnection(sConnString);
sqlConn.Open();
string commandText = String.Format("SELECT * FROM dbo.ParentFullInfo WHERE ISDId = {0}", Utilities.getISDId());
SqlCommand sqlCommand = new SqlCommand(commandText, sqlConn);
sqlDataReader = sqlCommand.ExecuteReader();
while (sqlDataReader.Read())
{
var parent = new Parent() { Students = new List<Student>() };
parent.Id = Convert.ToInt32(sqlDataReader["ParentId"]);
parent.ParentName = sqlDataReader["ParentName"].ToString();
parent.EmailAddress = sqlDataReader["EmailAddress"].ToString();
parent.Address = sqlDataReader["Address"].ToString();
parent.City = sqlDataReader["City"].ToString();
parent.State = sqlDataReader["State"].ToString();
parent.ZipCode = sqlDataReader["ZipCode"].ToString();
parent.WorkNumber = sqlDataReader["WorkNumber"] == DBNull.Value ? string.Empty : sqlDataReader["WorkNumber"].ToString();
parent.PrimaryCellNumber = sqlDataReader["PrimaryCellNumber"] == DBNull.Value ? string.Empty : sqlDataReader["PrimaryCellNumber"].ToString();
parent.HomeNumber = sqlDataReader["HomeNumber"] == DBNull.Value ? string.Empty : sqlDataReader["HomeNumber"].ToString();
parent.Password = sqlDataReader["Password"].ToString();
var student = StudentFactory.GetStudentByStudentId(Convert.ToInt32(sqlDataReader["StudentId"]));
if (!parents.Exists(p => p.Id == parent.Id))
{
parent.Students.Add(student);
parents.Add(parent);
}
else
{
var par = parents.FirstOrDefault(p => p.Id == parent.Id);
if (par != null)
par.Students.Add(student);
}
}
}
finally
{
if (sqlDataReader != null) sqlDataReader.Close();
if (sqlConn != null) sqlConn.Close();
}
return parents;
}
my Web.config does have the proper key
<add key="SMARTDBConn" value="server=ConnStringHere" />
The error
[InvalidOperationException: The ConnectionString property has not been initialized.]
System.Data.SqlClient.SqlConnection.PermissionDemand() +6616256
System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions) +6610951
System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry) +233
System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry) +278
System.Data.SqlClient.SqlConnection.Open() +239
SMART_Library.Factories.StudentFactory.GetStudentByStudentId(Int32 studentId) +138
SMART_Library.Factories.ParentFactory.GetParentsWithAssignedStudentsByISDId() +1378
SMARTSupport.Controllers.ParentController.Search(String SearchKey) +48
lambda_method(Closure , ControllerBase , Object[] ) +127
System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +270
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +39
System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +120
System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +452
System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +15
System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +33
System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +240
System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +28
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +74
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +42
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +606
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +288