When I say "not tested", this is because I have not installed an environment with exactly the same setup as you have described and I have given to you the setup that I would did in the same case.
In this post you mentioned "You must log in first".
Nowhere in the scenario that I provided you it is mentioned something from the front-end.
The scenarion that I given to you is for a creation of a slave site from the back-end. Not from the front-end.
It seems that you try creating a slave site from the front-end.
Does my assumption is correct ?
If you want to create a slave site from the front-end, the procedure is different.
In this case you can get inspired from the tutorial video 13 and you effectivelly need to login first.
In this case, you have to modify the JMS Template rule to use {site_prefix} and compute a {site_id}.
If you want that we setup the environment for you, this is possible with our billable support that you can order at
www.jms2win.com/download?page=shop.produ...35&category_id=1