diff --git a/CHANGELOG.md b/CHANGELOG.md
index f84dc790..c0718686 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,12 @@
 
 ## vX.Y.0 (future)
 
+## v2.20250504.0
+
+Small release with quick workaround fix for issue #4251 (Nil assertion failed).
+
+PR: https://github.com/iv-org/invidious/issues/5263
+
 ## v2.20250314.0
 
 ### Wrap-up
diff --git a/config/config.example.yml b/config/config.example.yml
index d6119f29..8d3e6212 100644
--- a/config/config.example.yml
+++ b/config/config.example.yml
@@ -90,14 +90,14 @@ db:
 ##
 ## API key for Invidious companion, used for securing the communication
 ## between Invidious and Invidious companion.
-## The size of the key needs to be more or equal to 16.
+## The key needs to be exactly 16 characters long.
 ##
 ## Note: This parameter is mandatory when Invidious companion is enabled
 ## and should be a random string.
 ## Such random string can be generated on linux with the following
 ## command: `pwgen 16 1`
 ##
-## Accepted values: a string
+## Accepted values: a string (of length 16)
 ## Default: <none>
 ##
 #invidious_companion_key: "CHANGE_ME!!"
diff --git a/src/invidious/routes/video_playback.cr b/src/invidious/routes/video_playback.cr
index b1c788c2..083087a9 100644
--- a/src/invidious/routes/video_playback.cr
+++ b/src/invidious/routes/video_playback.cr
@@ -21,7 +21,7 @@ module Invidious::Routes::VideoPlayback
     end
 
     # Sanity check, to avoid being used as an open proxy
-    if !host.matches?(/[\w-]+.googlevideo.com/)
+    if !host.matches?(/[\w-]+\.(?:googlevideo|c\.youtube)\.com/)
       return error_template(400, "Invalid \"host\" parameter.")
     end
 
@@ -37,7 +37,8 @@ module Invidious::Routes::VideoPlayback
 
     # See: https://github.com/iv-org/invidious/issues/3302
     range_header = env.request.headers["Range"]?
-    if range_header.nil?
+    sq = query_params["sq"]?
+    if range_header.nil? && sq.nil?
       range_for_head = query_params["range"]? || "0-640"
       headers["Range"] = "bytes=#{range_for_head}"
     end