Value cannot be null. Parameter name: source

[realworld666]

System.ArgumentNullException: Value cannot be null.
Parameter name: source
   at System.Linq.Enumerable.Where[TSource](IEnumerable`1 source, Func`2 predicate)
   at Cyclestreets.Pages.LiveRide.<<generatelinesegments>b__10_0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<throwasync>b__3(Object state)
   at BugSense.Core.BugSenseSyncContextHandler.AsyncSynchronizationContext.<>c__DisplayClass10.<wrapcallback>b__f(Object state)