I just modified my password and now with no underscore and capital. It works !
Hereunder the image of the articles: First row I submitted the exported XML manually to CrossRef and the rest by using plugin. This is it… the password has special character, but I don’t know about capital letter in password.
Under the Action tab do you think it should be Update rather than Register? and under the status of the manually submitted should be submitted?
This is the last view of the status after I hit Register 
and hit Update of the manually submitted article
