diff --git a/pyrobosim/pyrobosim/core/world.py b/pyrobosim/pyrobosim/core/world.py
index 14c3dac0..be036488 100644
--- a/pyrobosim/pyrobosim/core/world.py
+++ b/pyrobosim/pyrobosim/core/world.py
@@ -51,6 +51,7 @@ def __init__(
         self.hallways = []
         self.locations = []
         self.objects = []
+        self.set_metadata()
 
         # Counters
         self.num_rooms = 0
diff --git a/pyrobosim/pyrobosim/utils/general.py b/pyrobosim/pyrobosim/utils/general.py
index 5643a582..e98d249a 100644
--- a/pyrobosim/pyrobosim/utils/general.py
+++ b/pyrobosim/pyrobosim/utils/general.py
@@ -40,9 +40,16 @@ def __init__(self, filename):
         :param filename: Path to metadata YAML file.
         :type filename: str
         """
-        self.filename = filename
-        with open(self.filename) as file:
-            self.data = yaml.load(file, Loader=yaml.FullLoader)
+        if filename:
+            if not os.path.isfile(filename):
+                raise FileNotFoundError(f"Metadata filename not found: {filename}")
+
+            self.filename = filename
+            with open(self.filename) as file:
+                self.data = yaml.load(file, Loader=yaml.FullLoader)
+        else:
+            self.filename = None
+            self.data = {}
 
     def has_category(self, category):
         """