Unity 5 Windows phone 8 Crash on startup in wp8 device

I have a unity project 5 that I want to build for wp8. It only has one C # script. It also imports one custom package that I created. There are some default DLLs in the package that I want the application to be mandated with. I also have a few additional 10 libraries to be classed as optional. There can be at least 0 and a maximum of all 10 DLLs in the game. It is not necessary to use these DLLs. Only if you need additional functionality will you add them to the project.

Now what happens is ::

If I get my own package with 5 DLLs in the project, build it, open VS soln and run it, it works. this is the exception trace ::

{System.TypeInitializationException: The type initializer for "WinRTBridge.WinRTBridge" is throwing an exception. ---> System.TypeInitializationException: The type initializer for "WinRTBridge.TypeInformation" is throwing an exception. ---> System.IO.FileNotFoundException: Could not load file or assembly 'Windows, Version = 255.255.255.255, Culture = neutral, PublicKeyToken = null' or one of its dependencies. The system cannot find the file specified. in UnityEngineInternal.BootstrapHelpers.FillTypeMaps (Dictionary <code> 2 & typeToTypeIdMap, List 1 & typeIdToTypeMap) with WinRTBridge.TypeInformation..cctor () --- End of internal exception stack trace --- on WinRTBridge...TypeInformation WinRTBridge.WinRTBridge..cctor () --- End of the internal exception stack trace --- in WinRTBridge.WinRTBridge.set_Control (object value)
at Unity5Sample.MainPage..ctor ()}

I have my Windows Phone 8 sdk in place correctly and I can of course build, build and run sample wp8 projects in my Visual studio. So no question about some missing sdk for wp8.

But if I link to my own package and along with it, I also link to all the other 10 DLLs and then build it in unity and run it in Vs on the device, then it works fine.

There is no relationship between the dlls in my custom package and the ones we manually add later. But still this is what happens. Also, this only happens with Unity 5. With unit 4.5+ and <5.x, it works great no matter if I reference any of the optional 10 DLLs.