Description: This error occurs when the following webserver skins are applied:
To get around this, please follow the below steps:
Login to your console.
Click on the Canary you want to configure the webroot.
Click on “Configuration” and then “Configure Canary".
Scroll down to "WEBSERVER" and change the "HTTP Page Skin" to "Plain HTML". from the drop down list.
Once you have made the changes, you will need to deploy the new configurations.
Wait for the deployment to finish.
Once the deployment finishes, click on the Canary you're working with and click "Upload custom webroot" and follow the normal process.