iisnode encountered an error when processing the request.

HRESULT: 0x2
HTTP status: 500
HTTP subStatus: 1002
HTTP reason: Internal Server Error

You are receiving this HTTP 200 response because system.webServer/iisnode/@devErrorsEnabled configuration setting is 'true'.

In addition to the log of stdout and stderr of the node.exe process, consider using debugging and ETW traces to further diagnose the problem.

The last 64k of the output generated by the node.exe process to stderr is shown below:

(node:51320) UnhandledPromiseRejectionWarning: Error: Could not find a production build in the 'D:\leone\leone-client\.next' directory. Try building your app with 'next build' before starting the production server. https://nextjs.org/docs/messages/production-start-no-build-id
    at Server.readBuildId (D:\leone\leone-client\node_modules\next\dist\server\next-server.js:1872:23)
    at new Server (D:\leone\leone-client\node_modules\next\dist\server\next-server.js:104:29)
    at NextServer.createServer (D:\leone\leone-client\node_modules\next\dist\server\next.js:111:16)
    at async D:\leone\leone-client\node_modules\next\dist\server\next.js:123:31
(Use `node --trace-warnings ...` to show where the warning was created)
(node:51320) 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(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:51320) [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.
(node:51320) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.