Return a more specific error when inspect model folder doesn't exist

README.md

@@ -13,9 +13,9 @@ Provides nodes and API geared towards using ComfyUI as a backend for external to
 ## <a id="images" href="#toc">Sending and receiving images</a>
 
 ComfyUI exchanges images via the filesystem. This requires a
-multi-step process (upload images, prompt, download images), is rather
-inefficient, and invites a whole class of potential issues. It's also unclear
-at which point those images will get cleaned up if ComfyUI is used
+multi-step process (upload images, prompt, download images), which
+invites a whole class of potential issues you might not want to deal with.
+It's also unclear at which point those images will get cleaned up if ComfyUI is used
 via external tools.
 
 ### Load Image (Base64)

api.py

@@ -139,10 +139,14 @@ def inspect_diffusion_model(filename: str, model_type: str, is_checkpoint: bool)
 
 def inspect_models(model_type: str):
     try:
+        try:
+            files = folder_paths.get_filename_list(model_type)
+        except KeyError:
+            return {"error": f"Model folder not found: {model_type}"}
         is_checkpoint = model_type == "checkpoints"
         info = {
             filename: inspect_diffusion_model(filename, model_type, is_checkpoint)
-            for filename in folder_paths.get_filename_list(model_type)
+            for filename in files
         }
         return web.json_response(info)
     except Exception as e: