I noticed that in the project editor, this is possible:

I know it's not supposed to do that, and it doesn't look right, However, this only happens in C blocks like “If < > then” blocks.

If I run a script with this, it won't run no matter what cap block it is.

You do this by placing a C block, putting any non-cap block in there, and put a cap block above it. This also works with the “Forever” block.
So I'm not sure what is happening, or if this is a hard glitch and please respond if you have any differences.
Thank you for your time :)

I've been testing this for about 30 minutes, so I'm pretty sure it is correct.

I know this is weird, but what do you think the behavior should be? Not let you insert? Delete everything below? Other?

scubajerry wrote:

I know this is weird, but what do you think the behavior should be? Not let you insert? Delete everything below? Other?

Well, I think what you mean is what should the blocks do when it is incorrectly stacked? I don't think it should delete everything under. Not letting you insert would do it.

Strange, have you reported this to the scratch team?

kieran1002 wrote:

Strange, have you reported this to the scratch team?

Nope, I'll give @Lightnin* a link to this discussion.

Hmm… I suppose it should just work similarly to trying to put a variable inside a

block. Don't have the white line appear, and don't snap it in.

PullJosh wrote:

Hmm… I suppose it should just work similarly to trying to put a variable inside a

block. Don't have the white line appear, and don't snap it in.

Good Idea. Yeah. I think it used to, but I'm not exactly sure.

Ah hah! That is indeed a bug. Although it's basically just confined to the behavior of the blocks, right? It doesn't change the execution of the project.