Fatal error: Uncaught Error: Interface "Illuminate\Contracts\Validation\ValidationRule" not found in C:\Servers\htdocs\inventory.fitzalan.co.uk\app\Rules\UserCannotSwitchCompaniesIfItemsAssigned.php:9 Stack trace: #0 {main} thrown in C:\Servers\htdocs\inventory.fitzalan.co.uk\app\Rules\UserCannotSwitchCompaniesIfItemsAssigned.php on line 9