@David Stillman - There might be a few places to check. The first and easiest is probably the browser console to see which XHR request is giving the error. Then for the entire app, if you jump into Netsuite, then go to Setup -> SuiteCommerce Advanced -> SSP Applications you'll see a list of your SSPs. Just click on the name of whichever one you're using for your site (hopefully the 2019.1 dev app) and then go to the Execution Log sub-tab you should see any application-wide errors in there, But start with the console!