Add the following code to your Web.config file.
<system.codedom>
<compilers>
<compiler language="vb;vbs;visualbasic;vbscript" extension=".vb"
type="Microsoft.VisualBasic.VBCodeProvider, System,
Version=2.0.3600.0, Culture=neutral,
PublicKeyToken=b77a5c561934e089"
compilerOptions="path\AssemblyInfo.vb" />
</compilers>
</system.codedom>
<system.codedom>
<compilers>
<compiler language="c#;cs;csharp" extension=".cs"
type="Microsoft.CSharp.CSharpCodeProvider, System,
Version=2.0.3600.0, Culture=neutral,
PublicKeyToken=b77a5c561934e089" warningLevel="1"
compilerOptions="path\AssemblyInfo.cs" />
</compilers>
</system.codedom>