diff --git a/comfy/ldm/hunyuan3dv2_1/hunyuandit.py b/comfy/ldm/hunyuan3dv2_1/hunyuandit.py
index ca1a830014a1..d48d9d64209c 100644
--- a/comfy/ldm/hunyuan3dv2_1/hunyuandit.py
+++ b/comfy/ldm/hunyuan3dv2_1/hunyuandit.py
@@ -426,7 +426,7 @@ def __init__(
         text_states_dim=1024,
         qk_norm=False,
         norm_layer=nn.LayerNorm,
-        qk_norm_layer=nn.RMSNorm,
+        qk_norm_layer=True,
         qkv_bias=True,
         skip_connection=True,
         timested_modulate=False,
diff --git a/comfy_api/latest/_io.py b/comfy_api/latest/_io.py
index e0ee943a7a53..f770109d567b 100644
--- a/comfy_api/latest/_io.py
+++ b/comfy_api/latest/_io.py
@@ -1190,13 +1190,18 @@ def execute(cls, **kwargs) -> NodeOutput:
         raise NotImplementedError
 
     @classmethod
-    def validate_inputs(cls, **kwargs) -> bool:
-        """Optionally, define this function to validate inputs; equivalent to V1's VALIDATE_INPUTS."""
+    def validate_inputs(cls, **kwargs) -> bool | str:
+        """Optionally, define this function to validate inputs; equivalent to V1's VALIDATE_INPUTS.
+
+        If the function returns a string, it will be used as the validation error message for the node.
+        """
         raise NotImplementedError
 
     @classmethod
     def fingerprint_inputs(cls, **kwargs) -> Any:
-        """Optionally, define this function to fingerprint inputs; equivalent to V1's IS_CHANGED."""
+        """Optionally, define this function to fingerprint inputs; equivalent to V1's IS_CHANGED.
+
+        If this function returns the same value as last run, the node will not be executed."""
         raise NotImplementedError
 
     @classmethod