Why my ionic app is closed on browser and on terminal when i changed any content in my app or reload tab on browser second time?

When i run ionic serve first time then it will work well
but when i reload tab on browser then it will throw error like below

(node:6261) UnhandledPromiseRejectionWarning: Error [ERR_IPC_CHANNEL_CLOSED]: channel closed
at process.target.send (internal/child_process.js:578:16)
at taskError (/Users/di/Documents/mobile/demo/node_modules/@ionic/app-scripts/dist/worker-process.js:57:13)
at /Users/di/Documents/mobile/demo/node_

(node:6261) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:6261) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.