Weird and annoying bug - set up the stage before a show!

Hi. I have a singer, and recently a bug started happening with setting up the stage. Once I command "set up stage", my sim goes on the stage and does this thing with his hand, but then, instead of the stage being set up - everything on it disappears and my sim magically teleports next to the stage rather than on it. It doesn't matter if I try setting up the stage with a previously saved config or the one they give you.

Please help me! I can't perform.

Thanks.

P.S.
Just so you know, the only "custom content" I'm running is one house without any custom content in it, everything's original, from the game itself. And it can't be it because I ticked the "run without custom content" checkbox to see what happens, and the glitch still exists. Another thing that seemed weird to me: my EA/the sims 3/downloads folder has a few files in it: a file with the house "Hollywood Hills" and three more files called "msi", "nav", "wl" and another file which is named by my email address. Just thought these might cause the bug.

EDIT: READ HERE FIRST

So I found out that what's causing the problem is that he tries to go onto the stage with his casual clothes rather than his work cloths. So I need to change before the show, but it's still annoying.

Hello,

Those files should be there, don't worry. Hollywood Hills is probably the world.

Anyhow, what about Mods, do you have any?