[Bug] Nil assertion failed (NilAssertionError)

[DarkTankist]

Describe the bug
"Copyrighted" videos won't display

Steps to Reproduce

1. On the search bar write: "Beatles"
2. Open the first video

Logs

Title: `Nil assertion failed (NilAssertionError)
Date: `2025-07-16T08:58:52Z`
Route: `/watch?v=n2PNRTP49sk`
Version: `2025.05.17-f07859e @ (HEAD detached at v2.20250517.0)`

<details>
<summary>Backtrace</summary>
<p>

Nil assertion failed (NilAssertionError)
  from /usr/share/crystal/src/nil.cr:113:7 in 'not_nil!'
  from /usr/share/crystal/src/nil.cr:109:3 in 'not_nil!'
  from src/invidious/http_server/utils.cr:12:24 in 'proxy_video_url'
  from src/invidious/routes/watch.cr:128:32 in 'handle'
  from lib/kemal/src/kemal/route.cr:13:9 in '->'
  from src/invidious/helpers/handlers.cr:31:37 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call_next'
  from lib/kemal/src/kemal/filter_handler.cr:21:7 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call_next'
  from src/invidious/helpers/handlers.cr:95:12 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call_next'
  from src/ext/kemal_static_file_handler.cr:106:14 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call'
  from /usr/share/crystal/src/http/server/handler.cr:30:7 in 'call'
  from /usr/share/crystal/src/http/server/request_processor.cr:51:11 in 'handle_client'
  from /usr/share/crystal/src/fiber.cr:143:11 in 'run'
  from ???
</p>
</details>

Screenshots

Additional context

• Browser (if applicable): Firefox 140.0.4 (64-bit)
• OS (if applicable): Windows

[github-actions]

Hello, your issue is a duplicate of this/these issue(s):

• [Bug] Nil assertion failed (NilAssertionError) #5339 [accuracy: 100%]

If this is a mistake please explain why and ping @\unixfox, @\SamantazFox and @\TheFrenchGhosty.

Please refrain from opening new issues, it won't help in solving your problem.