An error occurred while creating an object. product

[Mac Group]

Hello everyone.

 

Im totally new to prestashop. I recently download prestashop 1.6.0.14

I then changed the theme, i have now tried to add a product, but i keep getting this error message An error occurred while creating an object. product 

 

When i added the template it didnt look exactly like the demo template, i then read if i wanted it to look the same, i should install the Demo site, which i did, it now looks like the template, but i cant add products

 

I have also noticed at the bottom of the page it says there are some files missing, please see attached screen shot. I am totally new to building websites, and feeling a bit lost...can anyone please help

 

my site is www.suayjewellery.com

 

Thanks in advance