fixed unicoil issue

app.py

@@ -18,14 +18,14 @@ except Exception as e:
     print(f"Error loading SPLADE model: {e}")
     print("Please ensure you have accepted any user access agreements on the Hugging Face Hub page for 'naver/splade-cocondenser-selfdistil'.")
 
+# Load UNICOIL model for binary sparse encoding
 # Load UNICOIL model for binary sparse encoding
 try:
-    # UNICOIL models are typically just AutoModel as they add a linear layer
-    # on top of a BERT-like encoder to predict weights.
-    # 'castorini/unicoil-msmarco-passage' is a common UNICOIL checkpoint.
     unicoil_model_name = "castorini/unicoil-msmarco-passage"
     tokenizer_unicoil = AutoTokenizer.from_pretrained(unicoil_model_name)
-    model_unicoil = AutoModel.from_pretrained(unicoil_model_name)
+    # --- FIX IS HERE ---
+    model_unicoil = AutoModelForMaskedLM.from_pretrained(unicoil_model_name)
+    # -------------------
     model_unicoil.eval() # Set to evaluation mode for inference
     print(f"UNICOIL model '{unicoil_model_name}' loaded successfully!")
 except Exception as e: