Unable to Reference PCL Project To Windows Phone 8.1(RT) Project in Xamarin Forms With Xlabs

Hi i created a xamarin forms(PCL) app. as it comes with WP 8.0 App(silver-light). so i removed and added a new Project WP 8.1(RT). i am successfully able to install xamarin forms and XLabs Nuget. but when i try to reference my PCL Core it is saying
"Error Type universe cannot resolve assembly: Xamarin.Forms.Platform.WP8, Version=1.4.0.0, Culture=neutral, PublicKeyToken=null. Error Cannot resolve Assembly or Windows Metadata file 'Xamarin.Forms.Platform.WP8.dll' Error The type "WindowsPhonePage" is abstract and must include an explicit value."

Please see Attachment.

But When i add a Silver-light Project is working Fine. So Now it is Not Possible to add a Run-time WP Project ? is there any workaround for this problem.?

Thank You