Column "columnName" does not belong to table "tableName"

I have a .NET console application deployed to an Azure VM. The utility is pretty simple, it just looks at a table and sends emails. However, we randomly get errors on this line:

foreach (DataRow bcemail in BCEmails.Tables[0].Rows)
{
email.Subject = bcemail["subject"].ToString(); 
//other stuff
}

The error we received says: column 'subject' does not belong to table Table. I have checked that the stored proc always returns only 1 table and always has "subject" as a column. Keep in mind it works more than half the times, giving error only randomly. It works totally fine in my local environment. The Azure VM also has several other apps. Researching this problem, I found this link: http://ift.tt/1K2hgIF Which talks about corrupted database connection pool and recommends that you make sure the connection is closed properly. I have done this throughout the application. The link also mentions that we use 'iisreset' every time we stop the IIS server. So I tried doing an IISReset and running the app again and it works fine. If I do an IISReset every time before it's scheduled to run, it works fine.

My questions are this: 1. This is a console app, not a web app, in fact there are no web sites configured on IIS on this VM. So why does IISReset work? 2. Can anyone recommend any other approach to solve this problem other than to do IISReset every time?

via Chebli Mohamed