Hello Adam,
Thank you for posting your question.
I understand what you are saying about the closed thread, but it’s actually intended to be a benefit to you that we close off older and resolved threads. By starting a new thread I am able to focus on just you and focus on your problem in a fresh way. Linking to similar issues is great! Having a nice clean thread with just you is really beneficial and allows me to give you quality support much easier then a thread with many voices.
It sounds like you may have the same issue that Kristen had.
Kristen had open_basedir in effect, and the solution was to move cp_themes to System to get around that. That’s not typical at all. Most of the time the themes folder is where you upload to which is in the docs. Here is the documentation on moving cp_themes to system.
Technically you can change the path/URL to where you keep themes, so the default location of themes/ is not set in stone. But in general most people leave this value as is. You may have open_basedir set (this is something your hosting provider can override for you) or maybe your path or URL to themes/ is set to system/. Does that make sense?
Is there anything else I can help with?
Cheers,