Error: an unknown error occurred while detecting CORS support

ZachLiu1

I got this message for my application.

Does anyone know what this means?

It seems not to bother the application.

ManishkumarPatel

I got this message for my application.

Does anyone know what this means?

It seems not to bother the application.

Cross-Origin Resource Sharing (CORS) allows web applications to bypass a browser's same origin policy. When both the web server and browser support CORS, a proxy  is not required to do cross-domain requests. This both simplifies  application development and potentially provides a performance boost.  Development is simplified because it is no longer necessary to maintain a  proxy page on your server. The performance boost comes from accessing a  resource directly rather than sending a request back to your server,  which then requests the specified URL and returns the result.

For further details please find the below link:
https://developers.arcgis.com/javascript/jshelp/inside_defaults.html
[h=4]Refer to the below:
esriConfig.defaults.io.corsDetection
esriConfig.defaults.io.corsEnabledServers
Hope this helps.

Best Regards,
Manish Patel