I am using
byte bytes = myReportViewer.LocalReport.Render("PDF");
File.WriteAllBytes("test.pdf", bytes); // I will normally return bytes here but for testing I am writing to a file
It seems that this was a known bug with Microsoft Reporting Services 10.0.0. After much googling, I stopped and checked my referenced files. It turns out that I was referencing version 10 of
Microsoft.Reporting.WebForms although in my other project that worked it was version 11.
So if anyone runs into the same problem, just make sure that you are not using the version 10 dll files.