I am developing a SPFX extension. While I am debug it at my SP online site using debug script, I found the icons are not showing up. Those icon are <i className="ms-Icon ms-Icon--PageEdit "
Also, in the F12 console I got following error:
Access to XMLHttpRequest at 'https://waconafd.officeapps.live.com/apc/trans.gif?4063a8778ee9a63a6f5f1234567890123' from origin 'https://mydomain.sharepoint.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.
I didn't intend to call waconafd.officeapps.live.com. I searched on my code files to verify this URL is not within my code. I guess one of the module or SP online is calling it. Is it normal? Is it the cause of icon missing?