Theme previews correctly but doesn't show up on live site

I am learning the new ways of working in the Plone 5 release. I used to just customize the css in the ZMI and that was it. The through the Plone way of working is confusing me and I am looking for help. I have done a considerable amount of reading and googling but am still feeling my way around in the dark.
I followed the instructions at this link:
When I preview the new theme in the Control Panel it appears fine and exactly as expected, but when I activate the theme I get an unstyled Plone.
If someone could point me to the steps to follow to get the theme to go live properly I would greatly appreciate it.

Thank you but never mind. I'm bailing from Plone 5 for now. I have a contract to deliver. I'm going to do it with Plone 4.

Would be happy to help figure it out but we would need to know more, like what theme you were using, how you were customizing it (what your changes were, and to which theme files), etc.

unstyled site could mean 'anything'. Maybe it is just the css that is missing. You should be able to see if the css file is not found in Firebug og something similar. If that is the case, you could try hardcoding the url to the css-file.

I have seen sites where http://ip:8080/somesite are unstyled and is styled because of this (and it is the same site).

Another good "reflex" when you run into styling problems is to look at the browser's inspector and check if there are errors in the console.

I've installed 4.3.10rc1 and have styled that using ploneCustom.css in the ZMI, the way I was used to working prior to Plone 5. I will have another look at Dexterity theming when I have the time.
To answer some questions, I copied Barceloneta theme in the Theming control panel in site setup. I built or compiled a css file called styles.css from the less file. Everything seemed to be in order, and when I previewed the theme it previewed correctly and as expected. When I enabled the theme I got an un-themed Plone. This was after much reading and research. It is just easier for me to use 4.3.10 and get on with the project. I do thank everyone for their help and appreciate their time and suggestions.