Protect alphas_cumprod from downcasting

modules/sd_models.py

@@ -387,7 +387,11 @@ def load_model_weights(model, checkpoint_info: CheckpointInfo, state_dict, timer
         if shared.cmd_opts.upcast_sampling and depth_model:
             model.depth_model = None
 
+        alphas_cumprod = model.alphas_cumprod
+        model.alphas_cumprod = None
         model.half()
+        model.alphas_cumprod = alphas_cumprod
+        model.alphas_cumprod_original = alphas_cumprod
         model.first_stage_model = vae
         if depth_model:
             model.depth_model = depth_model
@@ -642,6 +646,7 @@ def load_model(checkpoint_info=None, already_loaded_state_dict=None):
     else:
         weight_dtype_conversion = {
             'first_stage_model': None,
+            'alphas_cumprod': None,
             '': torch.float16,
         }