Exception: "Operation could destabilize the runtime" when running in Medium Trust

[ksouthworth]

I'm calling the "CsvWriter.WriteRecords()" function from an ASP.NET IHttpHandler (.ashx) running in Medium Trust, and it's throwing this exception:

[VerificationException: Operation could destabilize the runtime.]
lambda_method(ExecutionScope , CsvWriter , UserInfo ) +51
System.Action2.Invoke(T1 arg1, T2 arg2) +0 CsvWriter.WriteRecords(IEnumerable1 records) +353

"UserInfo" is just a C# class of mine that holds some user properties (username, email, etc.)

[ksouthworth]

[VerificationException: Operation could destabilize the runtime.]
   lambda_method(ExecutionScope , CsvWriter , UserInfo ) +51
   System.Action`2.Invoke(T1 arg1, T2 arg2) +0
   WA.FileHelpers.Csv.CsvWriter.WriteRecords(IEnumerable`1 records) +353

[ksouthworth]

Also, this is how I'm calling the WriteRecords function:

                    MemoryStream memoryStream = new MemoryStream();
                    StreamWriter streamWriter = new StreamWriter(memoryStream);
                    using (var csvWriter = new CsvWriter(streamWriter))
                    {
                        csvWriter.WriteRecords(storeCustomers);
                    }                    
                    StreamReader streamReader = new StreamReader(memoryStream);
                    string csvOutput = streamReader.ReadToEnd();      

[ksouthworth]

never mind, it had something to do with how i was opening/closing the streams/readers

[JoshClose]

OK. Closing.