Sometimes, The Vault may encounter a write error on a floppy disk. In this case, it tells you, and you are given the option to insert another disk to replace the bad one. When this is done, the new disk must be formatted to be at least as large as the old disk, i.e. it must hold the same amount of data or more. It is best to replace the old disk with one formatted in the same manner.
For example, if an error was found writing a single-sided 10-sector disk, The Vault requires that you replace it with a single-sided 10-sector disk, or a double-sided disk. If an error was found writing a double-sided 10-sector disk, another double-sided 10-sector disk is the only replacement.