I often got this error as following:

[ltn614]

No description provided.

[ltn614]

byte-code: Can't expand minibuffer to full frameError during redisplay: (eval undecided-unix) signaled (void-variable undecided-unix)

[ltn614]

like I simplely run the cmd : M-x help-with-tutorial-spec-language, it complains about:
byte-code: Can't expand minibuffer to full frame, Can U help me with that ?

[redguardtoo]

sorry, I can't. I also see this error happens sometimes. I just ignore it and retry. It looks is related to emacs version.

[ltn614]

I doubt that because when I use purcell‘s config or my old config I didn't get this issue while the emacs still the same version.

[redguardtoo]

add below code into .emacs, if it still exists, report bug at helm, it's helm issue.

(helm-mode 1)

(setq helm-completing-read-handlers-alist
      '((describe-function . ido)
        (describe-variable . ido)
        (debug-on-entry . helm-completing-read-symbols)
        (find-function . helm-completing-read-symbols)
        (find-tag . helm-completing-read-with-cands-in-buffer)
        (ffap-alternate-file . nil)
        (tmm-menubar . nil)
        (dired-do-copy . nil)
        (dired-do-rename . nil)
        (dired-create-directory . nil)
        (find-file . ido)
        (copy-file-and-rename-buffer . nil)
        (rename-file-and-buffer . nil)
        (w3m-goto-url . nil)
        (ido-find-file . nil)
        (ido-edit-input . nil)
        (mml-attach-file . ido)
        (read-file-name . nil)
        (yas/compile-directory . ido)
        (execute-extended-command . ido)
        (help-with-tutorial-spec-language . ido)
        (help-with-tutorial . ido)
        (read-language-name . ido)
        (minibuffer-completion-help . ido)
        (wg-load . ido)
        (rgrep . ido)
        (read-directory-name . ido)
        ))

[redguardtoo]

I reported to helm author and it's solved. please upgrade your helm and set up it (there is still some minor issue need be work arounded). anyway, check my commit for details:
0bd75f1 helm has issue with minibuffer (Chen Bin)

Here is the bug report on emacs-helm/helm#448

For helm setup, all you need is just one line, search
(help-with-tutorial . ido) in my init-helm.el

[redguardtoo]

Now we finally figured out, it's another package popwin.el which hooked helm function. I just remove it and everything fine now,

69bdc0c remove popwin because which has issue with helm (Chen Bin)