Merge pull request #869 from atravita-mods/patch-1

Add error message for invalid PNG

src/SMAPI/Framework/ContentManagers/ModContentManager.cs

@@ -254,6 +254,10 @@ namespace StardewModdingAPI.Framework.ContentManagers
             {
                 using FileStream stream = File.OpenRead(file.FullName);
                 using SKBitmap bitmap = SKBitmap.Decode(stream);
+
+                if (bitmap is null)
+                    throw new InvalidDataException($"Failed to load {file.FullName}. This doesn't seem to be a valid PNG image.");
+
                 rawPixels = SKPMColor.PreMultiply(bitmap.Pixels);
                 width = bitmap.Width;
                 height = bitmap.Height;