Many a times you require to use both C-Sharp (C#) and Visual Basic (VB) code class files in the same project.
If you just place your both the code files in your App_Code directly this is the error you’ll see,
“The files ‘/BlogEngine.Web/App_Code/VBCode/Class1.vb’ and ‘/BlogEngine.Web/App_Code/CSCode/Extensions/BreakPost.cs’ use a different language, which is not allowed since they need to be compiled together.”
But you can get this done, here is a very simple way you can try that out,
1) First make two folders in App_code with foldernames as
2) Modify the Web.config with following code:
<compilation debug="false"> <codeSubDirectories> <add directoryName="VBCode" /> <add directoryName="CSCode" /> </codeSubDirectories> </compilation>