add location in sequence yaml to FormatExceptions

OpenRA.Game/Graphics/Sequence.cs

@@ -40,6 +40,8 @@ namespace OpenRA.Graphics
 			var offset = float2.Zero;
 			var blendMode = BlendMode.Alpha;
 
+			try
+			{
 				if (d.ContainsKey("Start"))
 					Start = int.Parse(d["Start"].Value);
 
@@ -118,6 +120,11 @@ namespace OpenRA.Graphics
 						.F(unit, name, Start, Start + Facings * Stride - 1, srcOverride ?? unit, sprites.Length - 1,
 						info.Nodes[0].Location));
 			}
+			catch (FormatException f)
+			{
+				throw new FormatException("Failed to parse sequences for {0}.{1} at {2}:\n{3}".F(unit, name, info.Nodes[0].Location, f));
+			}
+		}
 
 		public Sprite GetSprite(int frame)
 		{