Fix for single source multi position images

src/Managers/ImageManager.Generation.cs

@@ -35,7 +35,7 @@ public static partial class ImageManager
 		}
 
 		string variant = null;
-		if (endpoint.Variants.Any() && TrueRandom.Next(0, 50) > 25)
+		if (endpoint.Variants != null && endpoint.Variants.Any() && TrueRandom.Next(0, 50) > 25)
 		{
 			variant = endpoint.Variants.Random().Name;
 		}
@@ -145,9 +145,11 @@ public static partial class ImageManager
 			}
 			
 			int img = 0;
-			foreach (var src in sources)
+			for(int x = 0; x < template.Positions.Count; x++)
 			{
-				var position = template.Positions.ElementAtOrDefault(img);
+				var position = template.Positions.ElementAtOrDefault(x);
+
+				var src = sources.ElementAtOrDefault(img);
 
 				Stream imageData = null;
 				if (File.Exists(src))
@@ -176,8 +178,11 @@ public static partial class ImageManager
 
 				image.Composite(tmp, Gravity.Northwest, position.X, position.Y, CompositeOperator.Over);
 
+				if (img + 1 < sources.Count())
+				{
 					img++;
 				}
+			}
 
 			return;
 		}