add reset max file and clear undo buffer in the callback of starting new scene

client/ayon_core/hosts/max/api/lib.py

@@ -6,12 +6,9 @@ import json
 from typing import Any, Dict, Union
 
 import six
-import ayon_api
 
 from ayon_core.pipeline import (
     get_current_project_name,
-    get_current_folder_path,
-    get_current_task_name,
     colorspace
 )
 from ayon_core.settings import get_project_settings

client/ayon_core/hosts/max/api/pipeline.py

@@ -52,11 +52,8 @@ class MaxHost(HostBase, IWorkfileHost, ILoadHost, IPublishHost):
 
         self._has_been_setup = True
 
-        def context_setting():
-            return lib.set_context_setting()
-
         rt.callbacks.addScript(rt.Name('systemPostNew'),
-                               context_setting)
+                               on_post_open)
 
         rt.callbacks.addScript(rt.Name('filePostOpen'),
                                lib.check_colorspace)
@@ -163,6 +160,12 @@ def ls() -> list:
         yield lib.read(container)
 
 
+def on_post_open():
+    lib.set_context_setting()
+    rt.resetMaxFile(rt.Name("noPrompt"))
+    rt.clearUndoBuffer()
+
+
 def containerise(name: str, nodes: list, context,
                  namespace=None, loader=None, suffix="_CON"):
     data = {