fix for situation when is null value or is not JObject

Author: arkadiuszbiel

.gitignore

@@ -111,3 +111,4 @@ src/Skybrud.Essentials/Skybrud.Essentials.csproj.DotSettings
 releases/nuget/Skybrud.Essentials.*/
 releases/github/Skybrud.Essentials.*/
 src/.vs/
+src/.idea/

src/Skybrud.Essentials/Json/Extensions/JObjectExtensions.cs

@@ -466,8 +466,9 @@ public static T[] GetArray<T>(this JObject obj, string path, Func<JObject, T> ca
             if (!(obj?.SelectToken(path) is JArray token)) return null;
 
             return (
-                from JObject child in token
-                select callback(child)
+                from child in token
+                where child is JObject
+                select callback((JObject)child)
             ).ToArray();
 
         }