Site Builder not working
Design and Skin Customization
The location for the skin in the database is:
TABLE: 'jr_jrcore_setting'
Locate the row of jrCore active_skin and change its value to whichever skin you want. It may take time to clear the caches if you have them on.
If you want to send me your admin login details I can take a look at what the warning/error is in site builder, but I'd need an admin account to see that section of the site.
Send details to support at jamroom dot net along with a link to this thread.