500 page error when I trigger google products plug-in

Hi,

Well, first, a 500 error doesn't help in understanding where the problem comes from so I can't give a precise solution.
I would recommend to check the PHP error log of your hosting. There, a fatal error message corresponding to the 500 HTTP error should be logged with precise information of where the error happened with the file path and line number. That would greatly help understanding what is wrong.
However, I see three main possibilities:
- you have a lot of products and thus too much data to load to generate the XML. In that case, you would have to increase the memory_limit and / or max_execution_time settings of your php.ini so that the process can run without hitting your hosting limits.
- you have a setting of the plugin not configured properly leading to an unforeseen error. For example, I see that you have entered only a price in the "shipping" setting. However, you're supposed to enter something like : FR::Standard:5.00 EUR
With the 2 letter country code and then :: then the name of the shipping method and then the amount. So not respecting that format could result in a fatal error. Similarly, in the "Identifier exists" setting, you need to enter either TRUE or FALSE but you entered "product_code". The rest of your settings looks fine.
- there is a real bug in HikaShop. In that case, the fatal error message from the PHP error log will be crutial to understand what's going on.