Reactive Extensions (Rx)

Fatal error: Uncaught exception 'GuzzleHttp\Exception\ClientException' with message 'Client error: `POST https://dc.services.visualstudio.com/v2/track` resulted in a `400 Invalid instrumentation key` response: {"itemsReceived":1,"itemsAccepted":0,"errors":[{"index":0,"statusCode":400,"message":"Invalid instrumentation key"}]} ' in D:\home\site\wwwroot\wp-content\plugins\wp-mail-smtp\vendor\guzzlehttp\guzzle\src\Exception\RequestException.php:113 Stack trace: #0 D:\home\site\wwwroot\wp-content\plugins\application-insights\vendor\guzzlehttp\guzzle\src\Middleware.php(66): GuzzleHttp\Exception\RequestException::create(Object(GuzzleHttp\Psr7\Request), Object(GuzzleHttp\Psr7\Response)) #1 D:\home\site\wwwroot\wp-content\plugins\wp-mail-smtp\vendor\guzzlehttp\promises\src\Promise.php(203): GuzzleHttp\Middleware::GuzzleHttp\{closure}(Object(GuzzleHttp\Psr7\Response)) #2 D:\home\site\wwwroot\wp-content\plugins\wp-mail-smtp\vendor\guzzlehttp\promises\src\Promise.php(156): GuzzleHttp\Promise\Promise::callHandler(1, Object(GuzzleHttp in D:\home\site\wwwroot\wp-content\plugins\wp-mail-smtp\vendor\guzzlehttp\guzzle\src\Exception\RequestException.php on line 113