diff --git a/scripts/startup/bl_operators/copy_global_transform.py b/scripts/startup/bl_operators/copy_global_transform.py
index 867695f5d9c..3260cd9ebfc 100644
--- a/scripts/startup/bl_operators/copy_global_transform.py
+++ b/scripts/startup/bl_operators/copy_global_transform.py
@@ -267,13 +267,28 @@ class OBJECT_OT_paste_transform(Operator):
         if not context.active_pose_bone and not context.active_object:
             cls.poll_message_set("Select an object or pose bone")
             return False
-
-        clipboard = context.window_manager.clipboard.strip()
-        if not (clipboard.startswith("Matrix(") or clipboard.startswith("<Matrix 4x4")):
-            cls.poll_message_set("Clipboard does not contain a valid matrix")
-            return False
         return True
 
+    @classmethod
+    def string_to_matrix(cls, value: str) -> Matrix | None:
+        if value.startswith("Matrix"):
+            return cls.parse_matrix(value)
+        if value.startswith("<Matrix 4x4"):
+            return cls.parse_repr_m4(value[12:-1])
+        if value:
+            return cls.parse_print_m4(value)
+        return None
+
+    @staticmethod
+    def parse_matrix(value: str) -> Matrix | None:
+        import ast
+        try:
+            return Matrix(ast.literal_eval(value[6:]))
+        except Exception:
+            # ast.literal_eval() can raise a slew of exceptions, all of
+            # which means that it's not a matrix on the clipboard.
+            return None
+
     @staticmethod
     def parse_print_m4(value: str) -> Optional[Matrix]:
         """Parse output from Blender's print_m4() function.
@@ -285,7 +300,11 @@ class OBJECT_OT_paste_transform(Operator):
         if len(lines) != 4:
             return None
 
-        floats = tuple(tuple(float(item) for item in line.split()) for line in lines)
+        try:
+            floats = tuple(tuple(float(item) for item in line.split()) for line in lines)
+        except ValueError:
+            # Apprently not the expected format.
+            return None
         return Matrix(floats)
 
     @staticmethod
@@ -296,22 +315,19 @@ class OBJECT_OT_paste_transform(Operator):
         if len(lines) != 4:
             return None
 
-        floats = tuple(tuple(float(item.strip()) for item in line.strip()[1:-1].split(',')) for line in lines)
+        try:
+            floats = tuple(tuple(float(item.strip()) for item in line.strip()[1:-1].split(',')) for line in lines)
+        except ValueError:
+            # Apprently not the expected format.
+            return None
         return Matrix(floats)
 
     def execute(self, context: Context) -> set[str]:
-        import ast
-
         clipboard = context.window_manager.clipboard.strip()
-        if clipboard.startswith("Matrix"):
-            mat = Matrix(ast.literal_eval(clipboard[6:]))
-        elif clipboard.startswith("<Matrix 4x4"):
-            mat = self.parse_repr_m4(clipboard[12:-1])
-        else:
-            mat = self.parse_print_m4(clipboard)
 
+        mat = self.string_to_matrix(clipboard)
         if mat is None:
-            self.report({'ERROR'}, "Clipboard does not contain a valid matrix")
+            self.report({'ERROR'}, "Clipboard does not contain a matrix")
             return {'CANCELLED'}
 
         try:
diff --git a/source/blender/blenkernel/intern/node_tree_update.cc b/source/blender/blenkernel/intern/node_tree_update.cc
index c30a5040ceb..5eb818e40f9 100644
--- a/source/blender/blenkernel/intern/node_tree_update.cc
+++ b/source/blender/blenkernel/intern/node_tree_update.cc
@@ -2189,6 +2189,7 @@ void BKE_ntree_update_after_single_tree_change(Main &bmain,
 
 void BKE_ntree_update_without_main(bNodeTree &tree)
 {
+  BLI_assert(tree.id.tag & ID_TAG_NO_MAIN);
   if (is_updating) {
     return;
   }
diff --git a/source/blender/editors/space_node/node_group.cc b/source/blender/editors/space_node/node_group.cc
index 1ea1fe0cc2c..e12469df2b4 100644
--- a/source/blender/editors/space_node/node_group.cc
+++ b/source/blender/editors/space_node/node_group.cc
@@ -242,6 +242,9 @@ static wmOperatorStatus node_group_enter_exit_invoke(bContext *C,
   if (!node->is_group()) {
     return OPERATOR_PASS_THROUGH;
   }
+  if (node->is_custom_group()) {
+    return OPERATOR_PASS_THROUGH;
+  }
   bNodeTree *group = id_cast<bNodeTree *>(node->id);
   if (!group || ID_MISSING(group)) {
     return OPERATOR_PASS_THROUGH;
diff --git a/source/blender/nodes/shader/node_shader_tree.cc b/source/blender/nodes/shader/node_shader_tree.cc
index 703f4785168..bb6d803d05a 100644
--- a/source/blender/nodes/shader/node_shader_tree.cc
+++ b/source/blender/nodes/shader/node_shader_tree.cc
@@ -437,12 +437,12 @@ static bool ntree_shader_implicit_closure_cast(bNodeTree *ntree)
     }
     else if ((link->fromsock->type == SOCK_SHADER) && (link->tosock->type != SOCK_SHADER)) {
       blender::bke::node_remove_link(ntree, *link);
-      BKE_ntree_update_after_single_tree_change(*G.main, *ntree);
+      BKE_ntree_update_without_main(*ntree);
       modified = true;
     }
   }
   if (modified) {
-    BKE_ntree_update_after_single_tree_change(*G.main, *ntree);
+    BKE_ntree_update_without_main(*ntree);
   }
   return true;
 }
@@ -736,7 +736,7 @@ static void ntree_shader_weight_tree_invert(bNodeTree *ntree, bNode *output_node
                                 *output_node,
                                 *thickness_output);
   }
-  BKE_ntree_update_after_single_tree_change(*G.main, *ntree);
+  BKE_ntree_update_without_main(*ntree);
 }
 
 static bool closure_node_filter(const bNode *node)
@@ -788,7 +788,7 @@ static void ntree_shader_shader_to_rgba_branches(bNodeTree *ntree)
       continue;
     }
     ntree_shader_copy_branch(ntree, shader_to_rgba, closure_node_filter);
-    BKE_ntree_update_after_single_tree_change(*G.main, *ntree);
+    BKE_ntree_update_without_main(*ntree);
 
     ntree_shader_weight_tree_invert(ntree, shader_to_rgba);
   }
@@ -981,7 +981,7 @@ static void ntree_shader_pruned_unused(bNodeTree *ntree, bNode *output_node)
   }
 
   if (changed) {
-    BKE_ntree_update_after_single_tree_change(*G.main, *ntree);
+    BKE_ntree_update_without_main(*ntree);
   }
 }