error "Odd number of elements in hashtable data

[ishi soichi]

I'm trying to develop a database using hash-table.

As you can see, creating a file that contains the data of hash-table.

(setq data-directory "~/(path)/hashtest")

(with-current-buffer (find-file-noselect data-directory)

  (let ((h (make-hash-table :test 'equal)))

    (puthash "think" "hard" h)

    (puthash "go" "this" h)

    (puthash "come" "that" h)

    (puthash "went" "gone" h)

    (puthash "category" "bad" h)

    (puthash "why" "how" h)

    (puthash "what" "on" h)

    (insert (format "%S" h))

    (save-buffer)))

in the "hashtest" file, 

#s(hash-table size 65 test equal rehash-size 1.5 rehash-threshold 0.8 data ("think" "hard" "go" "this" "come" "that" "went" "gone" "category" "bad" "why" "how" "what" "on" ...))

But for checking,

(with-current-buffer

    (find-file-noselect data-directory)

  (let ((ht (read (current-buffer))))

    (gethash "go" ht)))

gives an error, 

Debugger entered--Lisp error: (error "Odd number of elements in hashtable data")...

"Odd number" does not make sense to me at all.

Could anyone help me out?

Thanks in advance!

soichi