urgent: how to create a new Doctype folder in a collection

I am trying to insert a doctype folder to store non-XML files.
I can’t do it with Tamino X-Plorer and I don’t know why.
I do the following: I click the collection where I want to insert this doctype folder, then right button of the mouse and I choose “insert instance from non-xml file”. I write a new doctype name in this window and I select the option “non-XML instances” to insert my file and it appears a warning with the following information:
“Insert Instance from non-XML File”
“The specified doctype photos could not be found in the collection ‹XPLXPW0010›”
How can I solve it?
Do I need to insert any additional information in any schema of the collection where I want to create my doctype folder “photos”?
Thanks a lot,

Hello Diego,
This question is answered in your Support Request 634083. If you need more information please let me know through the SR.
Thanks and best regards