From c587686bcae80d6bc334f0cabdae88f65cd22cda Mon Sep 17 00:00:00 2001
From: phit <2097483+phit@users.noreply.github.com>
Date: Tue, 6 Oct 2026 00:30:10 +0200
Subject: [PATCH] fix: explain when the VR runtime refuses a session

Chrome only reports "The specified session configuration is not
supported" when SteamVR refuses a session, usually because another
browser holds the headset. Show what to do in the popup instead.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/generic.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/generic.js b/src/generic.js
index e5490c7..d9eb49c 100644
--- a/src/generic.js
+++ b/src/generic.js
@@ -191,7 +191,12 @@ function createController() {
             .catch((e) => {
                 console.warn('video2webxr: entering VR failed:', e);
                 stop();
-                lastError = `Entering VR failed: ${e.message}`;
+                // what Chrome reports when SteamVR refuses the session, usually because another
+                // browser already holds the headset
+                lastError =
+                    e.name === 'NotSupportedError'
+                        ? "The VR runtime couldn't start a session. Another browser or app may be using the headset: close it, or restart SteamVR, and try again."
+                        : `Entering VR failed: ${e.message}`;
             });
     }