update

app.py

@@ -59,6 +59,10 @@ def run_inference(
     )
     target = {i: {} for i in targets}
     if "affinity" in targets:
+        if protein_target == "" or not isinstance(protein_target, str):
+            raise ValueError(
+                f"Protein target must be specified for affinity prediction, not ={protein_target}"
+            )
         target["affinity"]["protein"] = protein_target
     else:
         protein_target = ""