TypeError: Cannot read properties of undefined (reading 'inaccessibleByURL') in `_updateURL`

[johanrd]

TypeError: Cannot read properties of undefined (reading 'inaccessibleByURL')

https://github.com/tildeio/router.js/blob/9320c7b1c1e887e73afd3700cd0093b9f34c9e6b/lib/router/router.ts#L669-L675

Stack trace from sentry:

[amk221]

Also started seeing this when enabling splitAtRoutes in an Embroider app