Hello,
These occur only on the Live Site only, not on staging. Of course, staging does not have the same traffic as production.
As I have said over and over, I cannot tell you what products are causing it or if it is just random. That is my answer to your question. Previously, you had access to the production site and were not able to duplicate. I did have it happen to me on the production site (the popup froze) and the error appeared, but when I reloaded and tried again with the same product, it was added just fine.
As you can see from our fatal error logs, this is occuring each day.
I think it may be related to cacheing. So, I will ask again: can you tell me a cache exclusion we should add that might effect the process or code that is running when the add to cart popup appears??? Or when this fatal error is generated?
Thank you.