Bulent - I know this is an old post, but hopefully there was some resolution to this.
I am currently having this same issue with the FileNotFoundException. I am using the 2015.1.420.45 release of Data Storage for Windows Universal (targeting Windows Phone 8.1).
I am able to run this on the emulator and deploy to a device if I build in debug mode. If I build in Release, I get the same error on both the emulator and when deployed to device.
at System.StubHelpers.StubHelpers.GetWinRTFactoryObject(IntPtr pCPCMD)
at Telerik_Storage.Database.GetOrCreateDatabase(String databaseName, DatabaseLocation location)
at Telerik.Storage.Extensions.Context..ctor(String databaseName, DatabaseLocation location)