Fatal error: Uncaught Error: Interface "Amp\Sync\Mutex" not found in C:\xampp\htdocs\londoncityroom\vendor\amphp\sync\src\SemaphoreMutex.php:8 Stack trace: #0 {main} thrown in C:\xampp\htdocs\londoncityroom\vendor\amphp\sync\src\SemaphoreMutex.php on line 8