hi. I have recently obtained org-googlecl.el, which enables to post from org
files directly.

https://github.com/rileyrg/org-googlecl/blob/master/org-googlecl.el

As mentioned in README file, the authentication is fine.  In fact, I can
post blogger entries from the command line without problem.
But every time I try to post an entry from Emacs by implementing M-x
org-googlecl-blog, it gives an error

Wrong type argument: characterp, sgml-xml-mode

Can anyone tell me what is wrong with my setting or whatever?

soichi