Error on ftp service OOPS: cannot locate user entry:nobody.

Symptoms: When trying to access the Linux ftp service it gives an error on client side, such as:
OOPS: cannot locate user entry:nobody.

Cause: By default, the vsftp service looks for this user even though there is no anonymous connection.
The message error is similar to this:
OOPS: cannot locate user entry:nobody.

Solution: Make sure it exists the Linux user called nobody.
Otherwise, create it, restart the ftp service and try again.