When I edit user data and try to save, I get an error:

Fatal error: Uncaught TypeError: in_array(): Argument #2 ($haystack) must be of type array, null given in /path/to/your/system/library/owc/owceuvat.php(194) : eval()'d code(1) : eval()'d code:685
Stack trace:
#0 /path/to/your/system/library/owc/owceuvat.php(194) : eval()'d code(1) : eval()'d code(685): in_array()
#1 /path/to/your/storage/modification/admin/controller/customer/customer.php(1168): OwcEUVat->checkEUVatCountry()
#2 /path/to/your/storage/modification/admin/controller/customer/customer.php(82): ControllerCustomerCustomer->validateForm()
#3 /path/to/your/storage/modification/system/engine/action.php(79): ControllerCustomerCustomer->edit()
#4 /path/to/your/admin/controller/startup/router.php(26): Action->execute()
#5 /path/to/your/storage/modification/system/engine/action.php(79): ControllerStartupRouter->index()
#6 /path/to/your/system/engine/router.php(67): Action->execute()
#7 /path/to/your/system/engine/router.php(56): Router->execute()
#8 /path/to/your/system/framework.php(179): Router->dispatch()
#9 /path/to/your/system/startup.php(104): require_once('...')
#10 /path/to/your/admin/index.php(19): start()
#11 {main} thrown in /path/to/your/system/library/owc/owceuvat.php(194) : eval()'d code(1) : eval()'d code on line 685