: Another application may be using the port. You can check which service is bound to it by running netstat -ano | findstr :11501 in a Windows Command Prompt or lsof -i :11501 on macOS/Linux.
While traffic bound to localhost is naturally protected from external internet threats, a few key security vectors must still be actively managed: localhost11501 exclusive
Where the "magic" happens before a site or app goes live. Why We’re Obsessed with Localized Content : Another application may be using the port