I have downloaded many custom maps on TWP. Some has good puzzle, but the downside is some models in game replaced with blue "ERROR!" sign. Is there texture error or error in my Portal 2?

Thanks

That's caused by the mapper forgetting to pak custom models into their map. Which file was it?

Normally, mappers here use to pack the custom content properly in our maps including models...

Ryoarmanda, have you got a legit copy of Portal2? Can you tell what maps are those that you play where that ERROR word appears in?

An example is Untitled by fedebenarg.

I'll post a screenshot here :

sp_untitled0000.jpg

Even in the downloaded file is just only the .bsp file, this still occur.
What should i do?

Thanks

2 indicators that you don't actually own a legal copy of Portal2:

1. You didn't answer to me after a direct question about it.

2. Since I've played that map, I can say that this map hasn't got much custom content. One of those checkerboard textures in your screenshot is the laser cube signage >.< ... other is the elevator screen texture used in the lightboard panel... and I bet that ERROR big word is the prop_monster_box model... NOTHING custom...

Hmmmm...

Let's not jump to conclusions here.

Your copy of Portal 2 is definitely very badly messed up. If you have a legal copy, verify integrity of game cache through Steam. That will solve the problems unless it's a pirated copy.