Sorry to spam. This is my GET method and there's clearly something I'm doing that is very stupid. I'm getting

Notice: There are no records of this type.

I think this was in your previous snippet where you have

id

as a query parameter. NetSuite reserves certain query parameters, so try using a different name, like invoiceID

context.request.parameters.invoiceID

i saw that, it's basically talking about namespaces when you search that notice in the doc. i swear i had this working before just like this.

I can't say it's definitely the issue, but it's SuiteAnswers 10607, which actually mentions your exact error message

If any of your parameters are named after any of the reserved parameter names, your Suitelet may throw an error saying, "There are no records of this type."

I changed it. Same error. I'm thinking that one of these is actually a custom record and I'm just naming things arbitrarily. Maybe 'invoice_sublist'? It has to do with the form because it only breaks when I try to writePage.