diff --git a/ui/loadout_manager_simple.py b/ui/loadout_manager_simple.py
index 30c92ee..eb55cb7 100644
--- a/ui/loadout_manager_simple.py
+++ b/ui/loadout_manager_simple.py
@@ -389,9 +389,9 @@ class LoadoutManagerDialog(QDialog):
     
     def _select_armor(self):
         """Open simplified armor selector."""
-        from ui.armor_selection_dialog import ArmorSelectionDialog
+        from ui.armor_selector import ArmorSelectorDialog
         
-        dialog = ArmorSelectionDialog(self)
+        dialog = ArmorSelectorDialog(self)
         if dialog.exec() == QDialog.DialogCode.Accepted:
             result = dialog.get_selected_armor()
             if result:
diff --git a/ui/weapon_selector.py b/ui/weapon_selector.py
index acc59c0..84037e6 100644
--- a/ui/weapon_selector.py
+++ b/ui/weapon_selector.py
@@ -4,7 +4,7 @@ Quick weapon selection for cost configuration.
 """
 
 import logging
-from decimal import Decimal
+from decimal import Decimal, InvalidOperation
 
 from PyQt6.QtWidgets import (
     QDialog, QVBoxLayout, QHBoxLayout, QLabel,
@@ -105,7 +105,22 @@ class WeaponSelectorDialog(QDialog):
         """Load weapons from API."""
         try:
             nexus = get_nexus_api()
-            self._weapons = nexus.get_all_weapons()
+            all_weapons = nexus.get_all_weapons()
+            
+            # Filter out weapons with invalid/null decay or ammo
+            self._weapons = []
+            for w in all_weapons:
+                try:
+                    # Validate that decay and ammo are valid numbers
+                    decay_val = w.decay if w.decay is not None else 0
+                    ammo_val = w.ammo if w.ammo is not None else 0
+                    # Try to convert to Decimal to validate
+                    Decimal(str(decay_val))
+                    Decimal(str(ammo_val))
+                    self._weapons.append(w)
+                except (InvalidOperation, ValueError, TypeError):
+                    # Skip weapons with invalid data
+                    continue
             
             # Sort by name
             self._weapons.sort(key=lambda w: w.name.lower())
@@ -120,25 +135,34 @@ class WeaponSelectorDialog(QDialog):
         self.weapon_list.clear()
         
         for weapon in weapons:
-            # Calculate cost per shot
-            decay_pec = Decimal(str(weapon.decay))
-            ammo = Decimal(str(weapon.ammo))
-            cost_per_shot = (decay_pec / Decimal("100")) + (ammo * Decimal("0.0001"))
-            
-            item = QListWidgetItem(f"{weapon.name} (💰 {cost_per_shot:.4f} PED)")
-            item.setData(Qt.ItemDataRole.UserRole, weapon)
-            
-            # Tooltip
-            tooltip = (
-                f"Damage: {weapon.damage}\n"
-                f"Decay: {weapon.decay} PEC\n"
-                f"Ammo: {weapon.ammo}\n"
-                f"Range: {weapon.range}\n"
-                f"DPP: {weapon.dpp:.2f}"
-            )
-            item.setToolTip(tooltip)
-            
-            self.weapon_list.addItem(item)
+            try:
+                # Get values with safe defaults
+                decay_raw = weapon.decay if weapon.decay is not None else 0
+                ammo_raw = weapon.ammo if weapon.ammo is not None else 0
+                
+                # Calculate cost per shot
+                decay_pec = Decimal(str(decay_raw))
+                ammo = Decimal(str(ammo_raw))
+                cost_per_shot = (decay_pec / Decimal("100")) + (ammo * Decimal("0.0001"))
+                
+                item = QListWidgetItem(f"{weapon.name} (💰 {cost_per_shot:.4f} PED)")
+                item.setData(Qt.ItemDataRole.UserRole, weapon)
+                
+                # Tooltip
+                tooltip = (
+                    f"Damage: {weapon.damage}\n"
+                    f"Decay: {decay_raw} PEC\n"
+                    f"Ammo: {ammo_raw}\n"
+                    f"Range: {weapon.range}\n"
+                    f"DPP: {weapon.dpp:.2f}" if weapon.dpp else "DPP: -"
+                )
+                item.setToolTip(tooltip)
+                
+                self.weapon_list.addItem(item)
+            except Exception as e:
+                # Skip weapons that fail to process
+                logger.debug(f"Skipping weapon {getattr(weapon, 'name', 'unknown')}: {e}")
+                continue
     
     def _on_search(self, text):
         """Filter weapons by search text."""
@@ -158,6 +182,24 @@ class WeaponSelectorDialog(QDialog):
         
         self.selected_weapon = weapon
         
+        # Get values with safe defaults
+        decay_raw = weapon.decay if weapon.decay is not None else 0
+        ammo_raw = weapon.ammo if weapon.ammo is not None else 0
+        
+        # Calculate cost per shot
+        decay_pec = Decimal(str(decay_raw))
+        ammo = Decimal(str(ammo_raw))
+        cost_per_shot = (decay_pec / Decimal("100")) + (ammo * Decimal("0.0001"))
+        
+        # Update preview
+        self.preview_name.setText(weapon.name)
+        self.preview_damage.setText(str(weapon.damage) if weapon.damage is not None else "-")
+        self.preview_decay.setText(f"{decay_raw} PEC")
+        self.preview_ammo.setText(str(ammo_raw))
+        self.preview_cost.setText(f"{cost_per_shot:.4f} PED")
+        
+        self.ok_btn.setEnabled(True)
+        
         # Calculate cost per shot
         decay_pec = Decimal(str(weapon.decay))
         ammo = Decimal(str(weapon.ammo))