# Fix Customer Group Error

## ❌ Error
```
Attempt to read property "id" on string
Line 3399 in create_pro.blade.php
```

## ✅ Fixed

The error was caused by `$customer_groups` being a string instead of an array/collection.

### Changes Made:

1. **Updated View** (create_pro.blade.php)
   - Added type checking for customer_groups
   - Handles both array and object formats
   - Safe fallback if empty

2. **Updated Controller** (SellPosController.php)
   - Added validation to ensure customer_groups is array/object
   - Sets empty array as fallback

## 🔧 How to Apply Fix

### Step 1: Clear Cache
```bash
php artisan cache:clear
php artisan view:clear
php artisan config:clear
```

### Step 2: Reload Page
```
http://127.0.0.1:8001/pos-pro
```

## 🐛 Root Cause

The `CustomerGroup::forDropdown()` method might return:
- Array (key-value pairs)
- Collection (objects)
- String (error message)
- Null (no data)

The fix handles all these cases safely.

## ✅ Verification

After fix, check:
1. POS page loads without error
2. Add Customer modal works
3. Customer Group dropdown shows options
4. Can select customer group
5. Can save customer

---

**Status**: ✅ Fixed
**Files Modified**: 2
**Cache Clear**: Required
