diff --git a/Htmldocs/release_notes.html b/Htmldocs/release_notes.html
index 141b5594..5c876379 100644
--- a/Htmldocs/release_notes.html
+++ b/Htmldocs/release_notes.html
@@ -56,6 +56,7 @@
       <li>[fix] Ignore old sessions should not impact existing data.</li>
       <li>[fix] Fix ocasional misordering of indexes on the Daily page.</li>
       <li>[fix] Add Unclassified Apneas to the Statistics page.</li>
+      <li>[fix] Resolve empty CPAP data card zips on macOS Big Sur.</li>
     </ul>
     <p>
     <b>Changes and fixes in OSCAR v1.2.0</b>
diff --git a/oscar/mainwindow.cpp b/oscar/mainwindow.cpp
index b0e08b24..252f1328 100644
--- a/oscar/mainwindow.cpp
+++ b/oscar/mainwindow.cpp
@@ -2712,8 +2712,28 @@ void MainWindow::on_actionCreate_Card_zip_triggered()
         bool ok = z.Open(filename);
         if (ok) {
             ProgressDialog * prog = new ProgressDialog(this);
+            
+            // Very full cards can sometimes take nearly a minute to scan,
+            // so display the progress dialog immediately.
+            prog->setMessage(tr("Calculating size..."));
+            prog->setWindowModality(Qt::ApplicationModal);
+            prog->open();
+
+            // Build the list of files.
+            FileQueue files;
+            bool ok = files.AddDirectory(cardPath, prefix);
+
+            // If there were any unexpected errors scanning the media, add the debug log to the zip.
+            if (!ok) {
+                qWarning() << "Unexpected errors when scanning SD card, adding debug log to zip.";
+                QString debugLog = logger->logFileName();
+                files.AddFile(debugLog, prefix + "-debug.txt");
+            }
+
             prog->setMessage(tr("Creating zip..."));
-            ok = z.AddDirectory(cardPath, prefix, prog);
+
+            // Create the zip.
+            ok = z.AddFiles(files, prog);
             z.Close();
         } else {
             qWarning() << "Unable to open" << filename;
diff --git a/oscar/zip.cpp b/oscar/zip.cpp
index def2b80a..80f7409a 100644
--- a/oscar/zip.cpp
+++ b/oscar/zip.cpp
@@ -168,6 +168,14 @@ bool FileQueue::AddDirectory(const QString & path, const QString & prefix)
     QDir dir(path);
     if (!dir.exists() || !dir.isReadable()) {
         qWarning() << dir.canonicalPath() << "can't read directory";
+#if defined(Q_OS_MACOS)
+        // If this is a directory known to be protected by macOS "Full Disk Access" permissions,
+        // skip it but don't consider it an error.
+        static const QSet<QString> s_macProtectedDirs = { ".fseventsd", ".Spotlight-V100", ".Trashes" };
+        if (s_macProtectedDirs.contains(dir.dirName())) {
+            return true;
+        }
+#endif
         return false;
     }
     QString base = prefix;
@@ -190,14 +198,12 @@ bool FileQueue::AddDirectory(const QString & path, const QString & prefix)
             qWarning() << "skipping symlink" << canonicalPath << fi.symLinkTarget();
         } else if (fi.isDir()) {
             // Descend and recurse
-            ok = AddDirectory(canonicalPath, relative_path);
+            ok &= AddDirectory(canonicalPath, relative_path);
         } else {
             // Add the file to the zip
-            ok = AddFile(canonicalPath, relative_path);
-        }
-        if (!ok) {
-            break;
+            ok &= AddFile(canonicalPath, relative_path);
         }
+        // Don't stop in our tracks when we hit an error.
     }
 
     return ok;