diff --git a/server/lib/player-media-health.js b/server/lib/player-media-health.js
index 4322fd8..b0bc2d9 100644
--- a/server/lib/player-media-health.js
+++ b/server/lib/player-media-health.js
@@ -13,8 +13,11 @@
 //
 // Dependency-free UMD: Node (require) + browser/Tizen (window.PlayerMediaHealth).
 (function (root, factory) {
-  if (typeof module === 'object' && module.exports) module.exports = factory();
-  else root.PlayerMediaHealth = factory();
+  // BOTH, not either/or — see schedule-eval.js. Node integration in a BrightSign widget made the
+  // browser branch unreachable, so the player ran without its media-health decision there.
+  var api = factory();
+  if (typeof module === 'object' && module.exports) module.exports = api;
+  if (root) root.PlayerMediaHealth = api;
 })(typeof self !== 'undefined' ? self : this, function () {
   'use strict';
 
diff --git a/server/lib/schedule-eval.js b/server/lib/schedule-eval.js
index 79b76fa..01a8de2 100644
--- a/server/lib/schedule-eval.js
+++ b/server/lib/schedule-eval.js
@@ -22,8 +22,13 @@
 // Dependency-free UMD: Node (require) + browser/Tizen (window.ScheduleEval).
 
 (function (root, factory) {
-  if (typeof module === 'object' && module.exports) module.exports = factory();
-  else root.ScheduleEval = factory();
+  // BOTH, not either/or: a BrightSign widget runs with Node integration, so `module` exists in
+  // page scope and an `else` left root.ScheduleEval undefined there. The player falls back to
+  // "always active" when it is missing — i.e. per-item DAYPARTING silently stopped applying on
+  // that platform, and scheduled content played outside its window with nothing in any log.
+  var api = factory();
+  if (typeof module === 'object' && module.exports) module.exports = api;
+  if (root) root.ScheduleEval = api;
 })(typeof self !== 'undefined' ? self : this, function () {
   'use strict';
 
diff --git a/server/player/index.html b/server/player/index.html
index fb11b79..a695560 100644
--- a/server/player/index.html
+++ b/server/player/index.html
@@ -3152,12 +3152,36 @@
     // the frame on screen now, as a texturable (CORS-clean) source: the live <img>, or — so a wipe can
     // start FROM a playing clip — a snapshot canvas of the outgoing <video>'s current frame. Returns null
     // if nothing on screen is texturable yet (first item after boot, un-decoded, or tainted) -> hard cut.
+    // Does a <video> on THIS platform actually yield pixels to a canvas?
+    //
+    // On a hardware video plane (BrightSign hwz, Tizen AVPlay) the answer is no, and the failure is
+    // silent: drawImage() succeeds, throws nothing, and paints a fully TRANSPARENT frame. The
+    // transition then runs with a blank `from` or `to` texture — a wipe from nothing, behind a video
+    // plane that is still lit. isMediaReadable() cannot catch it: it answers "am I ALLOWED to read
+    // this" (CORS), which is a different question from "did any pixels arrive".
+    //
+    // videoFrameIsCapturable() already asks the right question (a 16x16 ALPHA probe, so a genuine
+    // fade-to-black still reads as captured) but was only ever wired into the screenshot path.
+    // Cached because the answer is a property of the platform, not of the clip.
+    let _videoCompositingOk = null;
+    function videoCompositingAvailable(v) {
+      if (_videoCompositingOk !== null) return _videoCompositingOk;
+      if (!v || v.readyState < 2 || !v.videoWidth) return true;   // undecided — don't cache a guess
+      _videoCompositingOk = videoFrameIsCapturable(v);
+      if (!_videoCompositingOk) {
+        console.log('[transition] video frames are not readable on this platform (hardware plane) — ' +
+                    'transitions involving video will hard-cut; image-to-image still wipes');
+      }
+      return _videoCompositingOk;
+    }
+
     function currentTexturableFrame() {
       const c = document.getElementById('playerContainer');
       if (!c) return null;
       const img = c.querySelector('img');
       if (img && img.complete && img.naturalWidth > 0 && isMediaReadable(img)) return img;
       const v = c.querySelector('video');
+      if (v && !videoCompositingAvailable(v)) return null;   // hardware plane -> no from-frame -> hard cut
       if (v && v.readyState >= 2 && v.videoWidth > 0 && isMediaReadable(v)) {
         try {
           const r = c.getBoundingClientRect();
@@ -3456,7 +3480,12 @@
         && item.mime_type.startsWith('video/') && item.mime_type !== 'video/youtube'
         && !item.widget_id && !wallConfig && !isZones && !groupSync
         && item.transition && Array.isArray(item.transition.effects) && item.transition.effects.length
-        && transitionRuntimeReady();
+        && transitionRuntimeReady()
+        // A platform whose video sits on a hardware plane cannot supply the incoming frame either:
+        // the warm-play snapshot comes back transparent, so the wipe would fade in from nothing.
+        // `null` means "not yet determined" and is treated as available — the probe needs a
+        // playing video, and the first one on a fresh player has not run yet.
+        && _videoCompositingOk !== false;
       if (isVideoBufferable) {
         renderVideoBuffered(item);
         return;
diff --git a/server/test/player-transition-hardware-plane.test.js b/server/test/player-transition-hardware-plane.test.js
new file mode 100644
index 0000000..6844bf7
--- /dev/null
+++ b/server/test/player-transition-hardware-plane.test.js
@@ -0,0 +1,142 @@
+'use strict';
+
+/*
+ * Two bugs meet in this file, and the second only becomes reachable once the first is fixed.
+ *
+ * 1. The transition runtime never loaded on BrightSign. `transitionRuntimeReady()` is a presence
+ *    check on three globals and touches no WebGL at all — so "transitions don't work on BrightSign"
+ *    was never a GPU story. A BrightSign roHtmlWidget runs with `nodejs_enabled: true`, which puts
+ *    Node's `module` into classic-script scope, so every UMD module that exported with an `else`
+ *    took the CommonJS branch and never assigned its browser global.
+ *
+ * 2. Once the runtime DOES load there, video transitions would run against blank textures. On a
+ *    hardware video plane `drawImage(video)` succeeds, throws nothing, and paints a fully
+ *    TRANSPARENT frame — so the wipe fades from nothing, behind a video plane that is still lit.
+ *    Fixing (1) without (2) is therefore a REGRESSION: visibly worse than today's hard cut.
+ *
+ * The guard already existed for screenshots (`videoFrameIsCapturable`, an ALPHA probe) and simply
+ * was not wired into the transition path, which asked `isMediaReadable()` — a CORS question, i.e.
+ * "am I allowed to read this", not "did any pixels arrive".
+ */
+const { test } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('fs');
+const path = require('path');
+
+const ROOT = path.join(__dirname, '..', '..');
+const read = (p) => fs.readFileSync(path.join(ROOT, p), 'utf8');
+const PLAYER = read('server/player/index.html');
+
+// ---------------------------------------------------------------- UMD export shape
+
+// Every module a browser is meant to see must assign its global UNCONDITIONALLY. An `else` against
+// a `module`/`module.exports` test is the bug: it is invisible everywhere except a page with Node
+// integration, where it silently removes the global and every consumer falls back.
+const BROWSER_SHARED_MODULES = [
+  ['shared/Transitions/params.js', 'TransitionParams'],
+  ['shared/Transitions/renderer.js', 'TransitionRenderer'],
+  ['server/lib/schedule-eval.js', 'ScheduleEval'],
+  ['server/lib/player-media-health.js', 'PlayerMediaHealth'],
+  ['server/lib/media-mute.js', 'MediaMute'],
+  ['server/lib/orientation-style.js', 'OrientationStyle'],
+  ['server/lib/wall-geometry.js', 'WallGeometry'],
+  ['tizen/js/transitions.js', 'TransitionParams'],
+];
+
+for (const [file, globalName] of BROWSER_SHARED_MODULES) {
+  test(`#BS-UMD: ${file} exports ${globalName} without an else`, () => {
+    const src = read(file);
+    // The exact hazard: a CommonJS test whose ELSE branch is the only path to the browser global.
+    const elseHazard = /module\.exports[^\n]*\n?\s*(\}\s*)?else\b/.test(src)
+      || /if\s*\(\s*typeof module[^)]*\)\s*module\.exports[^\n]*\n\s*else\b/.test(src);
+    assert.equal(elseHazard, false,
+      `${file} exports its browser global from an else branch — invisible except under Node ` +
+      `integration (BrightSign), where the global silently never appears`);
+    assert.ok(
+      new RegExp(`(self|root|window)\\.${globalName}\\s*=`).test(src),
+      `${file} must assign ${globalName} for browsers`,
+    );
+  });
+}
+
+test('#BS-UMD: the runtime check is a plain global presence test, so a missing global IS the outage', () => {
+  // Documents WHY the export shape matters this much: nothing here touches WebGL, so a module-format
+  // problem and a GPU problem are indistinguishable from the outside.
+  const fn = PLAYER.slice(PLAYER.indexOf('function transitionRuntimeReady()'));
+  const body = fn.slice(0, fn.indexOf('}') + 1);
+  assert.match(body, /window\.TransitionRenderer/);
+  assert.match(body, /window\.TransitionParams/);
+  assert.match(body, /window\.__TRANSITION_SHADERS/);
+  assert.ok(!/getContext|webgl/i.test(body), 'this check must not be mistaken for a WebGL probe');
+});
+
+// ---------------------------------------------------------------- hardware-plane guard
+
+// Extract a function body out of index.html by brace matching — the established pattern in this
+// suite (see player-capture-hardware-plane.test.js).
+function extract(name) {
+  const at = PLAYER.indexOf(`function ${name}(`);
+  assert.ok(at > 0, `${name} not found`);
+  let i = PLAYER.indexOf('{', at), depth = 0, end = i;
+  for (; end < PLAYER.length; end++) {
+    if (PLAYER[end] === '{') depth++;
+    else if (PLAYER[end] === '}' && --depth === 0) { end++; break; }
+  }
+  return PLAYER.slice(at, end);
+}
+
+// A canvas whose pixels we control, so "video produced nothing" is expressible.
+function fakeCanvas(alpha) {
+  return {
+    width: 0, height: 0,
+    getContext: () => ({
+      drawImage() { /* succeeds and paints nothing, exactly like a hardware plane */ },
+      getImageData: (x, y, w, h) => ({ data: new Uint8ClampedArray(w * h * 4).fill(0).map((_, i) => (i % 4 === 3 ? alpha : 0)) }),
+    }),
+  };
+}
+
+function runCapturable(alpha) {
+  const src = extract('videoFrameIsCapturable');
+  const fn = new Function('document', `${src}; return videoFrameIsCapturable;`)({
+    createElement: () => fakeCanvas(alpha),
+  });
+  return fn({ readyState: 4, videoWidth: 1920 });
+}
+
+test('#BS-guard: a transparent frame means the pixels never arrived', () => {
+  assert.equal(runCapturable(0), false, 'alpha 0 across the probe is a hardware plane, not a video');
+});
+
+test('#BS-guard: a genuine fade-to-black is still a captured frame', () => {
+  // The biconditional that makes the probe honest: black pixels are opaque, so a legitimately dark
+  // frame must NOT be mistaken for "nothing arrived" — otherwise every fade would hard-cut.
+  assert.equal(runCapturable(255), true, 'opaque black is a real frame');
+});
+
+test('#BS-guard: the transition path consults capturability, not just CORS', () => {
+  const fn = extract('currentTexturableFrame');
+  assert.match(fn, /videoCompositingAvailable/,
+    'the outgoing frame must be gated on whether pixels actually arrive');
+  // isMediaReadable answers a different question and must not be the only gate on the video branch.
+  const videoBranch = fn.slice(fn.indexOf("querySelector('video')"));
+  assert.ok(videoBranch.indexOf('videoCompositingAvailable') < videoBranch.indexOf('isMediaReadable'),
+    'the capturability guard must run BEFORE the CORS check short-circuits the branch');
+});
+
+test('#BS-guard: an incoming video is not buffered for a wipe it cannot supply', () => {
+  const at = PLAYER.indexOf('const isVideoBufferable');
+  assert.ok(at > 0);
+  const decl = PLAYER.slice(at, PLAYER.indexOf(';', at));
+  assert.match(decl, /_videoCompositingOk !== false/,
+    'image→video would otherwise fade in from a transparent texture');
+  assert.match(decl, /transitionRuntimeReady\(\)/, 'the runtime is still required');
+});
+
+test('#BS-guard: undetermined is treated as available, so a fresh player is not crippled', () => {
+  // The probe needs a playing video; the first item on a cold start has not run one. Defaulting to
+  // "unavailable" would disable video transitions everywhere until a video happened to play.
+  const fn = extract('videoCompositingAvailable');
+  assert.match(fn, /return true/, 'an undecided probe must not latch off');
+  assert.match(fn, /_videoCompositingOk !== null/, 'the platform answer must be cached once known');
+});
diff --git a/shared/Transitions/params.js b/shared/Transitions/params.js
index a161530..49c9015 100644
--- a/shared/Transitions/params.js
+++ b/shared/Transitions/params.js
@@ -69,8 +69,16 @@ const VERTEX = `attribute vec2 aPos;
 varying vec2 vUv;
 void main(){ vUv = aPos * 0.5 + 0.5; gl_Position = vec4(aPos, 0.0, 1.0); }`;
 
+// Export to BOTH, never either/or. A BrightSign roHtmlWidget is created with
+// `nodejs_enabled: true`, which puts Node's `module` into the page's classic-script scope — so an
+// `else` here means the browser branch never runs on that platform and `self.TransitionParams` is
+// simply never set. The player's transitionRuntimeReady() is a presence check on exactly that
+// global, so transitions were dark on every BrightSign, and the failure looked like a GPU problem
+// rather than a module-format one. Anything a browser is meant to see must be assigned
+// unconditionally.
 if (typeof module !== 'undefined' && module.exports) {
   module.exports = { parseParams, resolveParams, PREAMBLE, EPILOGUE, VERTEX };
-} else if (typeof self !== 'undefined') {
+}
+if (typeof self !== 'undefined') {
   self.TransitionParams = { parseParams, resolveParams, PREAMBLE, EPILOGUE, VERTEX }; // browser (player/demo)
 }
diff --git a/shared/Transitions/renderer.js b/shared/Transitions/renderer.js
index 177292b..ae34a4b 100644
--- a/shared/Transitions/renderer.js
+++ b/shared/Transitions/renderer.js
@@ -8,9 +8,13 @@
 //
 // Never-blank teeth live here too: on `webglcontextlost` the renderer flips `lost` and calls
 // opts.onContextLost so the player can hard-cut to a plain <img> instead of showing black.
+// Exports to BOTH targets — see the note in params.js. On BrightSign (`nodejs_enabled: true`)
+// `module` exists in page scope, so an `else` leaves root.TransitionRenderer undefined and the
+// whole transition runtime silently absent.
 (function (root, factory) {
-  if (typeof module !== 'undefined' && module.exports) module.exports = factory();
-  else root.TransitionRenderer = factory();
+  var api = factory();
+  if (typeof module !== 'undefined' && module.exports) module.exports = api;
+  if (root) root.TransitionRenderer = api;
 })(typeof self !== 'undefined' ? self : this, function () {
   'use strict';
 
diff --git a/tizen/js/schedule-eval.js b/tizen/js/schedule-eval.js
index 79b76fa..01a8de2 100644
--- a/tizen/js/schedule-eval.js
+++ b/tizen/js/schedule-eval.js
@@ -22,8 +22,13 @@
 // Dependency-free UMD: Node (require) + browser/Tizen (window.ScheduleEval).
 
 (function (root, factory) {
-  if (typeof module === 'object' && module.exports) module.exports = factory();
-  else root.ScheduleEval = factory();
+  // BOTH, not either/or: a BrightSign widget runs with Node integration, so `module` exists in
+  // page scope and an `else` left root.ScheduleEval undefined there. The player falls back to
+  // "always active" when it is missing — i.e. per-item DAYPARTING silently stopped applying on
+  // that platform, and scheduled content played outside its window with nothing in any log.
+  var api = factory();
+  if (typeof module === 'object' && module.exports) module.exports = api;
+  if (root) root.ScheduleEval = api;
 })(typeof self !== 'undefined' ? self : this, function () {
   'use strict';
 
diff --git a/tizen/js/transitions.js b/tizen/js/transitions.js
index b8227e0..740213d 100644
--- a/tizen/js/transitions.js
+++ b/tizen/js/transitions.js
@@ -69,9 +69,11 @@ const VERTEX = `attribute vec2 aPos;
 varying vec2 vUv;
 void main(){ vUv = aPos * 0.5 + 0.5; gl_Position = vec4(aPos, 0.0, 1.0); }`;
 
+// Hand-committed copy of shared/Transitions — keep the both-targets export in step with it.
 if (typeof module !== 'undefined' && module.exports) {
   module.exports = { parseParams, resolveParams, PREAMBLE, EPILOGUE, VERTEX };
-} else if (typeof self !== 'undefined') {
+}
+if (typeof self !== 'undefined') {
   self.TransitionParams = { parseParams, resolveParams, PREAMBLE, EPILOGUE, VERTEX }; // browser (player/demo)
 }
 
@@ -87,8 +89,9 @@ if (typeof module !== 'undefined' && module.exports) {
 // Never-blank teeth live here too: on `webglcontextlost` the renderer flips `lost` and calls
 // opts.onContextLost so the player can hard-cut to a plain <img> instead of showing black.
 (function (root, factory) {
-  if (typeof module !== 'undefined' && module.exports) module.exports = factory();
-  else root.TransitionRenderer = factory();
+  var api = factory();
+  if (typeof module !== 'undefined' && module.exports) module.exports = api;
+  if (root) root.TransitionRenderer = api;
 })(typeof self !== 'undefined' ? self : this, function () {
   'use strict';