Curious case of IISExpress error “Failed to register URL” when working with OWINHost

when working with an application using a bunch of micro services , ran into this error with iisexpress Failed to register URL “http://localhost:3001/” for site “Contoso.Web” application “/”. Error descriptio n: Cannot create a file when that file already exists. (0x800700b7) C:\Program Files\IIS Express>iisexpress /config:D:\PROJECTS\api\.vs\config\applicationhost.config /trace:error Starting IIS Express … Initializing the W3 Server Started…