diff --git a/act/front_end/spec_creator_base.py b/act/front_end/spec_creator_base.py
index 98df08aa4..bd0ff2872 100644
--- a/act/front_end/spec_creator_base.py
+++ b/act/front_end/spec_creator_base.py
@@ -327,7 +327,9 @@ def _validate_output_spec_shape(
             (is_valid, error_message) tuple
         """
         if spec.kind in [OutKind.MARGIN_ROBUST, OutKind.TOP1_ROBUST]:
-            if not (0 <= spec.y_true < num_classes):
+            y_true_valid_class = (0 <= spec.y_true).logical_and(spec.y_true < num_classes)
+
+            if not y_true_valid_class.all():
                 return False, f"Class label {spec.y_true} out of range [0, {num_classes})"
         
         elif spec.kind == OutKind.LINEAR_LE:
diff --git a/act/front_end/torchvision_loader/create_specs.py b/act/front_end/torchvision_loader/create_specs.py
index b55ce2af8..eb60c8283 100644
--- a/act/front_end/torchvision_loader/create_specs.py
+++ b/act/front_end/torchvision_loader/create_specs.py
@@ -464,7 +464,7 @@ def _validate_and_filter_specs(
         
         for input_spec, output_spec in spec_pairs:
             try:
-                is_valid = self.validate_spec_pair_with_model(
+                is_valid, errors = self.validate_spec_pair_with_model(
                     input_spec,
                     output_spec,
                     pytorch_model,
@@ -475,8 +475,8 @@ def _validate_and_filter_specs(
                     valid_pairs.append((input_spec, output_spec))
                 else:
                     logger.debug(
-                        f"Spec pair validation failed: "
-                        f"{input_spec.kind}, {output_spec.kind}"
+                        f"Spec pair validation failed: {input_spec.kind}, {output_spec.kind}, with errors:\n"
+                        f"{"\n".join(errors)}"
                     )
             
             except Exception as e:
diff --git a/act/front_end/vnnlib_loader/create_specs.py b/act/front_end/vnnlib_loader/create_specs.py
index 21dae0eac..f1036ba05 100644
--- a/act/front_end/vnnlib_loader/create_specs.py
+++ b/act/front_end/vnnlib_loader/create_specs.py
@@ -281,7 +281,7 @@ def _validate_and_filter_specs(
         
         for input_spec, output_spec in spec_pairs:
             try:
-                is_valid = self.validate_spec_pair_with_model(
+                is_valid, errors = self.validate_spec_pair_with_model(
                     input_spec,
                     output_spec,
                     pytorch_model,
@@ -292,8 +292,8 @@ def _validate_and_filter_specs(
                     valid_pairs.append((input_spec, output_spec))
                 else:
                     logger.debug(
-                        f"Spec pair validation failed: "
-                        f"{input_spec.kind}, {output_spec.kind}"
+                        f"Spec pair validation failed: {input_spec.kind}, {output_spec.kind}, with errors:\n"
+                        f"{"\n".join(errors)}"
                     )
             
             except Exception as e: