Registration page crashes with "Cannot read properties of null (reading 'parentNode')" after hydration mismatch

Error

TypeError: Cannot read properties of null (reading 'parentNode')

Stack trace

$RS (app:///registration?flow=76206bf1-1557-4d0e-b47d-f1d3c6ad3244:1:47576)
  ← ? (app:///registration?flow=76206bf1-1557-4d0e-b47d-f1d3c6ad3244:1:47645)

(Minified inline script; $RS is React's internal Suspense-boundary stream-resume helper — no further source context available.)

Request context

• URL: https://main.devguard.org/registration?flow=76206bf1-1557-4d0e-b47d-f1d3c6ad3244
• Culprit route: /registration
• Referer: https://main.devguard.org/login?flow=22921e4d-0cc2-4978-b5d4-a33520ea50f1
• A breadcrumb shows React error #418 (hydration mismatch) fired ~4ms before this error on the same page load — same recurring hydration issue seen in issue 3305, 3368, 3370, and 3379 — now confirmed on a 5th route. This parentNode TypeError looks like a downstream failure in React's Suspense stream-resume ($RS) triggered once hydration has already failed, rather than an independent bug.

GlitchTip

• Issue: https://error-tracking.devguard.org/devguard/issues/3386
• Event ID: 019fc7030fa8736fa3ebffd710bc23f8
• First seen: 2026-08-03T09:44:54.262Z

Start at the /registration route and compare its hydration behavior with the recurring reports in issues 3305, 3368, 3370, and 3379. Reproduce the flow using the provided registration URL and confirm that React error #418 and the downstream parentNode crash no longer occur after the hydration issue is addressed.