Error: "Code blocks are not allowed in this file" after upgrade to 2013

We have one custom Site Page with some server side script. The page used to work in 2010 but after upgrade to 2013, it's giving the error: "Code blocks are not allowed in this file". I've tried the following enteries in web.config file:

• <PageParserPath VirtualPath="/sites/engineering/SitePages/DMS.aspx" CompilationMode="Always" AllowServerSideScript="true"/>
• <PageParserPath VirtualPath="/SitePages/DMS.aspx" CompilationMode="Always" AllowServerSideScript="true"/>
• <PageParserPath VirtualPath="/sites/engineering/*" CompilationMode="Always" AllowServerSideScript="true" IncludeSubFolders="true"/>

None of them worked. The actual url for the page is http://servername/sites/engineering/SitePages/DMS.aspx 

i'm modifying the web.config at C:\inetpub\wwwroot\wss\VirtualDirectories\80.

Any ideas?

Thanks.