Agent undefined error in next.js page router in custom _document after upgrading to from 13.2.1 -> 13.4.0

[EvertLagerberg]

Description

We have this setup in a next.js 14 page router application:
https://github.com/newrelic/newrelic-node-examples/blob/9415503f3bd78fa5d87a7214596d51c946199474/nextjs/nextjs-legacy/pages/_document.jsx

    if (newrelic.agent.collector.isConnected() === false) {
      await new Promise((resolve) => {
        newrelic.agent.on("connected", resolve)
      })
    }

After upgrading from version 13.2.1 to 13.4.0 we started getting this error
TypeError: Cannot read properties of undefined (reading 'collector') at....

Seems like the new relic agent is undefined?

Expected Behavior

We expect to be able to check if the agent is connected or not and according to documentation we should not need any null checks

Steps to Reproduce

Set up for next.js with page router according to examples.

Your Environment

Node version: 22
Version: between 13.2.1 and 13.4.0

[Newrelic-Boomi]

https://new-relic.atlassian.net/browse/NR-483216

[amychisholm03]

Hi @EvertLagerberg , thank you for bringing this to our attention. I have ran the example you linked with Next.js 14.2.32, Node 22.17.1, and newrelic 13.4, and I am unable to reproduce the issue. For issues like this, I recommend leveraging our support team over at support.newrelic.com which can help deep-dive into solving the problem. They will also ask to collect the necessary information which may or may not be sensitive (such as logs).

[bizob2828]

@EvertLagerberg I'm going to go ahead and close this. If for some reason you can provide a reproduction case, please reopen, but as @amychisholm03 mentioned, it may be best to work this issue through support. The only thing I can think of, is this is crashing because you don't have a proper license key so the agent isn't started and not assigning newrelic.agent.collector