diff --git a/arc_solver/dsl.py b/arc_solver/dsl.py
index 7c3e80e..57ca245 100644
--- a/arc_solver/dsl.py
+++ b/arc_solver/dsl.py
@@ -190,8 +190,13 @@ def pad(a: Array, top: int, bottom: int, left: int, right: int, fill_value: int
 def apply_program(a: Array, program: List[Tuple[str, Dict[str, Any]]]) -> Array:
     """Apply a sequence of operations to the input grid."""
     out = a
-    for name, params in program:
-        out = apply_op(out, name, params)
+    for idx, (name, params) in enumerate(program):
+        try:
+            out = apply_op(out, name, params)
+        except Exception as exc:
+            raise ValueError(
+                f"Failed to apply operation '{name}' at position {idx} with params {params}"
+            ) from exc
     return out
 
 
diff --git a/arc_solver/neural/guidance.py b/arc_solver/neural/guidance.py
index b1a37d8..9d33c41 100644
--- a/arc_solver/neural/guidance.py
+++ b/arc_solver/neural/guidance.py
@@ -144,12 +144,17 @@ class NeuralGuidance:
     def __init__(self, model_path: Optional[str] = None):
         self.heuristic_guidance = HeuristicGuidance()
         self.neural_model = None
-        
+        expected_dim = 17
+
         if model_path and os.path.exists(model_path):
-            self.load_model(model_path)
+            try:
+                self.load_model(model_path)
+                if getattr(self.neural_model, "input_dim", expected_dim) != expected_dim:
+                    raise ValueError("model input dimension mismatch")
+            except Exception:
+                self.neural_model = SimpleClassifier(expected_dim)
         else:
-            # For now, create a dummy neural model
-            self.neural_model = SimpleClassifier(17)  # 17 features
+            self.neural_model = SimpleClassifier(expected_dim)
     
     def predict_operations(self, train_pairs: List[Tuple[Array, Array]]) -> List[str]:
         """Predict which operations are likely relevant for the task."""
diff --git a/arc_solver/neural/sketches.py b/arc_solver/neural/sketches.py
index f752b13..48c50cb 100644
--- a/arc_solver/neural/sketches.py
+++ b/arc_solver/neural/sketches.py
@@ -209,5 +209,26 @@ def generate_parameter_grid(operation: str, constraints: Dict[str, Any] = None)
         return [{'dy': dy, 'dx': dx} for dy in dy_range for dx in dx_range]
     elif operation == 'identity':
         return [{}]
+    elif operation == 'crop':
+        tops = range(3) if 'top' not in constraints else constraints['top']
+        lefts = range(3) if 'left' not in constraints else constraints['left']
+        heights = range(1, 4) if 'height' not in constraints else constraints['height']
+        widths = range(1, 4) if 'width' not in constraints else constraints['width']
+        return [
+            {"top": t, "left": l, "height": h, "width": w}
+            for t in tops for l in lefts for h in heights for w in widths
+        ]
+    elif operation == 'pad':
+        out_h = range(5, 20) if 'out_h' not in constraints else constraints['out_h']
+        out_w = range(5, 20) if 'out_w' not in constraints else constraints['out_w']
+        return [{"out_h": h, "out_w": w} for h in out_h for w in out_w]
+    elif operation == 'recolor':
+        mappings = []
+        colors = range(10)
+        for src in colors:
+            for dst in colors:
+                if src != dst:
+                    mappings.append({"mapping": {src: dst}})
+        return mappings
     else:
-        return [{}]  # Default empty params for other operations
+        return [{}]  # Default empty params for unknown operations
diff --git a/arc_solver/search.py b/arc_solver/search.py
index 80d62ba..23cbf73 100644
--- a/arc_solver/search.py
+++ b/arc_solver/search.py
@@ -32,12 +32,36 @@ def enumerate_programs(depth: int = 2) -> List[List[Tuple[str, Dict[str, int]]]]
             for dy in range(-2, 3)
             for dx in range(-2, 3)
         ],
-        "recolor": [],  # Recolor handled separately via heuristics
-        "crop": [],
-        "pad": [],
+        "crop": [
+            {"top": t, "left": l, "height": h, "width": w}
+            for t in range(3)
+            for l in range(3)
+            for h in range(1, 4)
+            for w in range(1, 4)
+        ],
+        "pad": [
+            {"out_h": h, "out_w": w}
+            for h in range(5, 20)
+            for w in range(5, 20)
+        ],
+        "recolor": [
+            {"mapping": {i: j}}
+            for i in range(10)
+            for j in range(10)
+            if i != j
+        ],
         "identity": [{}],
     }
-    base_ops = ["rotate", "flip", "transpose", "translate", "identity"]
+    base_ops = [
+        "rotate",
+        "flip",
+        "transpose",
+        "translate",
+        "crop",
+        "pad",
+        "recolor",
+        "identity",
+    ]
     # Generate all length-1 programs
     if depth == 1:
         return [[(op, params)] for op in base_ops for params in param_space[op]]
@@ -108,4 +132,4 @@ def predict_two(
             except Exception:
                 outs.append(ti)
         attempts.append(outs)
-    return attempts
\ No newline at end of file
+    return attempts