diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index 7e3576f4bb..ec2f4a59a7 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -165,7 +165,15 @@ class IconResourceManager:
             q = os.path.join(self.override_icon_path, name)
             if os.path.exists(q):
                 return QIcon(q)
-        return QIcon.fromTheme(os.path.splitext(name.replace('\\', '__').replace('/', '__'))[0])
+        icon_name = os.path.splitext(name.replace('\\', '__').replace('/', '__'))[0]
+        ans = QIcon.fromTheme(icon_name)
+        if ans.isNull():
+            if 'user-any' in QIcon.themeName():
+                tc = 'dark' if QApplication.instance().is_dark_theme else 'light'
+                q = QIcon(f':/icons/calibre-default-{tc}/images/{name}')
+                if not q.isNull():
+                    ans = q
+        return ans
 
     def set_theme(self):
         current = QIcon.themeName()
diff --git a/src/calibre/gui2/icon_theme.py b/src/calibre/gui2/icon_theme.py
index 721cf030a6..5a8779886a 100644
--- a/src/calibre/gui2/icon_theme.py
+++ b/src/calibre/gui2/icon_theme.py
@@ -12,6 +12,7 @@ import math
 import os
 import sys
 import tempfile
+from contextlib import suppress
 from functools import lru_cache
 from io import BytesIO
 from itertools import count
@@ -468,12 +469,9 @@ def get_cover(metadata):
     etag_file, cover_file = map(path, 'etag jpg'.split())
 
     def safe_read(path):
-        try:
+        with suppress(FileNotFoundError):
             with open(path, 'rb') as f:
                 return f.read()
-        except OSError as e:
-            if e.errno != errno.ENOENT:
-                raise
         return b''
     etag, cached = safe_read(etag_file), safe_read(cover_file)
     etag = etag.decode('utf-8')
diff --git a/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp b/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
index 50a02347d7..2f8598cd94 100644
--- a/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
+++ b/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
@@ -157,7 +157,15 @@ int CalibreStyle::styleHint(StyleHint hint, const QStyleOption *option, const QW
 }
 
 QIcon CalibreStyle::standardIcon(StandardPixmap standardIcon, const QStyleOption * option, const QWidget * widget) const {
-    if (icon_map.contains(standardIcon)) return QIcon::fromTheme(icon_map.value(standardIcon));
+    if (icon_map.contains(standardIcon)) {
+        QIcon ans = QIcon::fromTheme(icon_map.value(standardIcon));
+        if (ans.isNull() && QIcon::themeName().contains("user-any")) {
+            const bool is_dark_theme = QApplication::instance()->property("is_dark_theme").toBool();
+            QIcon q(QString(":/icons/calibre-default-%1/images/%2.png").arg(is_dark_theme ? "dark" : "light").arg(icon_map.value(standardIcon)));
+            if (!q.isNull()) ans = q;
+        }
+        return ans;
+    }
     return QProxyStyle::standardIcon(standardIcon, option, widget);
 }