Bethesda should make a vault for Fallout 4 called Vault 404, where most of the computers work for a few minutes before giving a 404 error. Other things such as doors could also not work properly. The players pipboy could not work properly inside. To cement the whole 404 error thing, after reaching a certain point in the vault, the screen will go blue and bring up the classic "Error 404" screen, but lasts for only a minute or 2 before returning to the game.

There are only 122 Vaults...

This. But.

It's a funny idea though.

Easter Egg, maybe.

The easter egg was in Fallout 2; when the Vault 8 mainframe offered to to re-format the drive.

Simply name it Vault 40, with only the fourth level being accessible. There's no info on vault 40, thus gamesas can make something up.

Besides there being only 122 vaults in total, have you ever used a terminal in fallout? Don't really think they're capable of 404 error.... especially since 404 entails there being a broken or dead web link. Mysteriously, terminals in fallout cannot connect to the web. So no this is a bad idea.

Plus that sorry but, what would be the point for Vault-Tec to ever create such a vault?