I updated Woocommerce to the latest version, 3.3.3. I then used the system status report to find outdated templates within my custom theme. I updated all of them, and am now having issues.
When an order is processed, either two issues comes up. The card is declined for unsuccessful orders, or it gives an Internal Server Error notice if the order processes through the payment gateway.
I went back through, and double checked all of the template files to ensure that I didn't update any improperly. They have all been done correctly.
Next, I switched to the twentyseventeen theme, and disabled all plugins except Woocommerce and my payment gateway. After doing this, I was able to process orders normally. I started reactivating plugins to see if it was one of those.
I have yet to come up with an answer as to why I can't process orders normally. I'm assuming it is a theme issue, but the only updates were to template files. Are there any ways to find if a template file is not operating properly, and this is causing problems?