fix load_vae() to check size mismatch

Author: wkpark

modules/sd_vae.py

@@ -202,42 +202,52 @@ def load_vae(model, vae_file=None, vae_source="from unknown source"):
             # use vae checkpoint cache
             print(f"Loading VAE weights {vae_source}: cached {get_filename(vae_file)}")
             store_base_vae(model)
-            _load_vae_dict(model, checkpoints_loaded[vae_file])
+            loaded = _load_vae_dict(model, checkpoints_loaded[vae_file])
         else:
             assert os.path.isfile(vae_file), f"VAE {vae_source} doesn't exist: {vae_file}"
             print(f"Loading VAE weights {vae_source}: {vae_file}")
             store_base_vae(model)
 
             vae_dict_1 = load_vae_dict(vae_file, map_location=shared.weight_load_location)
-            _load_vae_dict(model, vae_dict_1)
+            loaded = _load_vae_dict(model, vae_dict_1)
 
-            if cache_enabled:
+            if loaded and cache_enabled:
                 # cache newly loaded vae
                 checkpoints_loaded[vae_file] = vae_dict_1.copy()
 
         # clean up cache if limit is reached
-        if cache_enabled:
+        if loaded and cache_enabled:
             while len(checkpoints_loaded) > shared.opts.sd_vae_checkpoint_cache + 1: # we need to count the current model
                 checkpoints_loaded.popitem(last=False)  # LRU
 
         # If vae used is not in dict, update it
         # It will be removed on refresh though
         vae_opt = get_filename(vae_file)
-        if vae_opt not in vae_dict:
+        if loaded and vae_opt not in vae_dict:
             vae_dict[vae_opt] = vae_file
 
     elif loaded_vae_file:
         restore_base_vae(model)
+        loaded = True
 
-    loaded_vae_file = vae_file
+    if loaded:
+        loaded_vae_file = vae_file
     model.base_vae = base_vae
     model.loaded_vae_file = loaded_vae_file
+    return loaded
 
 
 # don't call this from outside
 def _load_vae_dict(model, vae_dict_1):
+    conv_out = model.first_stage_model.state_dict().get("encoder.conv_out.weight")
+    # check shape of "encoder.conv_out.weight". SD1.5/SDXL: [8, 512, 3, 3], FLUX/SD3: [32, 512, 3, 3]
+    if conv_out.shape != vae_dict_1["encoder.conv_out.weight"].shape:
+        print("Failed to load VAE. Size mismatched!")
+        return False
+
     model.first_stage_model.load_state_dict(vae_dict_1)
     model.first_stage_model.to(devices.dtype_vae)
+    return True
 
 
 def clear_loaded_vae():
@@ -270,7 +280,7 @@ def reload_vae_weights(sd_model=None, vae_file=unspecified):
 
     sd_hijack.model_hijack.undo_hijack(sd_model)
 
-    load_vae(sd_model, vae_file, vae_source)
+    loaded = load_vae(sd_model, vae_file, vae_source)
 
     sd_hijack.model_hijack.hijack(sd_model)
 
@@ -279,5 +289,6 @@ def reload_vae_weights(sd_model=None, vae_file=unspecified):
 
     script_callbacks.model_loaded_callback(sd_model)
 
-    print("VAE weights loaded.")
+    if loaded:
+        print("VAE weights loaded.")
     return sd_model