diff --git a/client/ayon_core/lib/path_templates.py b/client/ayon_core/lib/path_templates.py
index 01a6985a25..33af503dd5 100644
--- a/client/ayon_core/lib/path_templates.py
+++ b/client/ayon_core/lib/path_templates.py
@@ -460,6 +460,34 @@ def validate_value_type(value):
                 return True
         return False
 
+    @staticmethod
+    def validate_key_is_matched(key):
+        """Validate that opening has closing at correct place.
+        Future-proof, only square brackets are currently used in keys.
+
+        Example:
+            >>> is_matched("[]()()(((([])))")
+            False
+            >>> is_matched("[](){{{[]}}}")
+            True
+
+        Returns:
+            bool: Openings and closing are valid.
+
+        """
+        mapping = dict(zip("({[", ")}]"))
+        opening = set(mapping.keys())
+        closing = set(mapping.values())
+        queue = []
+
+        for letter in key:
+            if letter in opening:
+                queue.append(mapping[letter])
+            elif letter in closing:
+                if not queue or letter != queue.pop():
+                    return False
+        return not queue
+
     def format(self, data, result):
         """Format the formattings string.
 
@@ -472,6 +500,12 @@ def format(self, data, result):
             result.add_output(result.realy_used_values[key])
             return result
 
+        # ensure key is properly formed [({})] properly closed.
+        if not self.validate_key_is_matched(key):
+            result.add_missing_key(key)
+            result.add_output(self.template)            
+            return result
+
         # check if key expects subdictionary keys (e.g. project[name])
         existence_check = key
         key_padding = list(KEY_PADDING_PATTERN.findall(existence_check))