diff --git a/gallery_dl/downloader/http.py b/gallery_dl/downloader/http.py
index 101baced..87ca71ba 100644
--- a/gallery_dl/downloader/http.py
+++ b/gallery_dl/downloader/http.py
@@ -308,6 +308,9 @@ class HttpDownloader(DownloaderBase):
             # download content
             self.downloading = True
             with pathfmt.open(mode) as fp:
+                if fp is None:
+                    # '.part' file no longer exists
+                    break
                 if file_header:
                     fp.write(file_header)
                     offset += len(file_header)
diff --git a/gallery_dl/path.py b/gallery_dl/path.py
index 1404b847..ff0c9649 100644
--- a/gallery_dl/path.py
+++ b/gallery_dl/path.py
@@ -171,6 +171,9 @@ class PathFormat():
         try:
             return open(self.temppath, mode)
         except FileNotFoundError:
+            if "r" in mode:
+                # '.part' file no longer exists
+                return util.NullContext()
             os.makedirs(self.realdirectory)
             return open(self.temppath, mode)