[23-Feb-2026 16:30:03 Africa/Blantyre] PHP Fatal error:  Uncaught Error: Call to undefined function getNextInvoiceNumber() in /home/smplus/powertex/supervisor/controllers/sales_controller.php:126
Stack trace:
#0 /home/smplus/powertex/supervisor/controllers/sales_controller.php(28): saveInvoice(Object(stock_model), Object(sales_model), Object(common_model), Object(PDO))
#1 {main}
  thrown in /home/smplus/powertex/supervisor/controllers/sales_controller.php on line 126
