Fixes Tribler#7473 FileNotFoundError when displaying the settings page

src/tribler/core/utilities/path_util.py

@@ -56,7 +56,14 @@ def size(self, include_dir_sizes: bool = True) -> int:
  for root, dir_names, file_names in os.walk(self):
  names = itertools.chain(dir_names, file_names) if include_dir_sizes else file_names
  paths = (os.path.join(root, name) for name in names)
- size += sum(os.path.getsize(p) for p in paths if os.path.exists(p))
+ for p in paths:
+ if os.path.exists(p):
+ try:
+ size += os.path.getsize(p)
+ except FileNotFoundError:
+ # In rare cases of race condition, it is possible that the file,
+ # such as `sqlite/knowledge.db-journal`, was deleted right after the `os.path.exists` check.
+ pass
  return size
 
  def startswith(self, text: str) -> bool: