You can look to other program window (a video player) looking to the sky when snowing in Minecraft

What you are describing isn't entirely clear. Can you attach a screenshot or a video?

I'll see if I can. Because when I took the screen capture, it wasn't appeared the bug.

I attached a screenshot. In this case, the video is about minecraft so you can see something like minecraft

Some thing happened

Don't Understand Not using English You can look to other program window (a video player) looking to the sky when snowing in Minecraft

It means it's been modified using outside software.

I could take a photo with my camera that shows the bug.

Maybe the problem is not by that. With the photo you will see what happens and if it's really a bug or only on my case.

Is Modded: Very likely; Jar signature invalidated

That's your problem. Re-download and it should be fixed.

The jar, right?