Adding Attribute value to Name Value

I have a Name Value attribute created for "Necklace Style" that I am trying to add 3 different types of styles to in a drop down box using the Attribute Value. I added one just fine & when I tried to add the next one, I get this message - "WARNING: An Error occurred, please refresh the page and try again."

I have refreshed the page and attempted to enter a new Attribute Value several times and I am unable to add anything. I've logged out and back into the admin panel and still it will not work.
I've tried creating a new Name Value attribute and adding attribute values to that, again getting the same message.

I'm a total newb at Zen Cart, PHP and my knowledge of SQL is very limited.
I am using version 1.5 and do not believe that there have been any updates applied. The install was via GoDaddy. I applied a template obtained via ZenCart free templates and have done some basic customization in regards to layout using the CSS and that's about it.

If anyone has any ideas on how I can get this problem fixed or even a decent work around I would really appreciate it, I am working on the project for a friend who's doing an online store.
Thanks :)

Start here:

https://www.zen-cart.com/tutorials/index.php?article=412

Thanks stevesh!!