There is already an open DataReader associated with this Command which must be closed first
This error occur if you forgot to include “MultipleActiveResultSets=True” in your connection string. It was actually on by default in VS 2005 but was later set to off. Here’s an example of a connection string w/ MARs set. SQL Server authentication: cnString = "Data Source=" & ServerName & ";Initial Catalog=" & DatabaseName & ";Persist Security Info=True;MultipleActiveResultSets=True;User ID=sa