fix(uxp): null-safe Time object access in readActiveSequence

getStartTime/getEndTime/getInPoint/getOutPoint can return null for
non-clip track items (gaps, transitions) that slip past the
getProjectItem check. Accessing .seconds on null threw a TypeError
that the outer catch swallowed — silently dropping every clip and
leaving clips[] empty, so the export panel never opened.

Also skip clips where all four time values resolve to 0 (filler items).

services/premiere-plugin-uxp/src/timeline.js

@@ -1,4 +1,4 @@
-// timeline.js — v2.1.5
+// timeline.js — v2.1.6
 // premierepro API: docs say sync, runtime returns Promises. Await everything.
 
 (function () {
@@ -11,23 +11,31 @@
     return Timeline._ppro;
   }
 
+  // Safe helper — returns the numeric seconds value from a Time object,
+  // or 0 if the object is null/undefined/malformed.
+  function _secs(t) {
+    if (!t) return 0;
+    if (typeof t.seconds === 'number') return t.seconds;
+    return 0;
+  }
+
   // ── Read active sequence ─────────────────────────────────────────
   Timeline.readActiveSequence = async function () {
     const P = ppro();
     const project = await P.Project.getActiveProject();
     if (!project) throw new Error('No active Premiere project');
     const seq = await project.getActiveSequence();
-    if (!seq) throw new Error('No active sequence');
+    if (!seq) throw new Error('No active sequence — open a sequence in the timeline first');
 
-    const name     = seq.name || (await seq.getName && await seq.getName()) || 'Sequence 1';
+    const name     = seq.name || (seq.getName ? await seq.getName() : '') || 'Sequence 1';
     const settings = await seq.getSettings();
     let frameRate = 29.97;
     try {
-      const fr = settings.videoFrameRate;
+      const fr = settings && settings.videoFrameRate;
       if (fr && typeof fr.seconds === 'number' && fr.seconds > 0) frameRate = 1 / fr.seconds;
     } catch (_) {}
-    const width  = settings.videoFrameWidth  || 1920;
+    const width  = (settings && settings.videoFrameWidth)  || 1920;
-    const height = settings.videoFrameHeight || 1080;
+    const height = (settings && settings.videoFrameHeight) || 1080;
 
     const clips      = [];
     const trackCount = await seq.getVideoTrackCount();
@@ -43,21 +51,30 @@
         try {
           const projItem = await clip.getProjectItem();
           if (!projItem) continue;
+
           let filePath = '';
           try {
             const clipItem = await P.ClipProjectItem.cast(projItem);
             filePath = await clipItem.getMediaFilePath() || '';
           } catch (_) {}
+
           const clipName = await clip.getName().catch(() => '');
           const fileName = clipName || (filePath ? path.basename(filePath) : 'clip');
-          const startT = await clip.getStartTime();
+
-          const endT   = await clip.getEndTime();
+          // Null-safe time access — non-clip items can return null Time objects
-          const inT    = await clip.getInPoint();
+          const startT = await clip.getStartTime().catch(() => null);
-          const outT   = await clip.getOutPoint();
+          const endT   = await clip.getEndTime().catch(() => null);
-          const tlIn   = startT.seconds;
+          const inT    = await clip.getInPoint().catch(() => null);
-          const tlOut  = endT.seconds;
+          const outT   = await clip.getOutPoint().catch(() => null);
-          const srcIn  = inT.seconds;
+
-          const srcOut = outT.seconds;
+          const tlIn   = _secs(startT);
+          const tlOut  = _secs(endT);
+          const srcIn  = _secs(inT);
+          const srcOut = _secs(outT);
+
+          // Skip filler/gap items where all times are zero
+          if (tlIn === 0 && tlOut === 0 && srcIn === 0 && srcOut === 0 && !filePath) continue;
+
           clips.push({
             fileName, filePath, trackIndex: ti,
             timelineInSec: tlIn, timelineOutSec: tlOut,
@@ -67,7 +84,9 @@
             sourceInFrames:    Math.round(srcIn  * frameRate),
             sourceOutFrames:   Math.round(srcOut * frameRate),
           });
-        } catch (_) {}
+        } catch (clipErr) {
+          console.warn('[df] readActiveSequence: skipped clip on track', ti, '—', clipErr && clipErr.message);
+        }
       }
     }
     return { sequenceName: name, frameRate, width, height, clips };
@@ -131,7 +150,7 @@
   Timeline.pushToMAM = async function (seqName, projectId, td) {
     const resolved = Library.resolveClipsToAssets(td.clips || []);
     const matched  = resolved.filter(c => c.asset_id);
-    if (!matched.length) throw new Error('No clips matched MAM assets — import proxies first');
+    if (!matched.length) throw new Error('No clips matched MAM assets — import proxies first so the plugin can map file paths to asset IDs');
     const seqs = await API.listSequences(projectId);
     let seqId;
     const existing = seqs.find(s => s.name === seqName);