Description: This error occurs when the following webserver skins are applied:

• IIS 7 Skin
• JBoss Login
• MS Sharepoint 2010 Login
• CUPS Web Interface

To get around this, please follow the below steps:

Step 1:

Log in to your Console.

Step 2:

Select the Canary you want to configure a custom webroot on.

Note: we have selected the CT-Office-01 Canary.

Step 3:

Click on Configure Canary.

Step 4:

1 - Scroll down to WEBSERVER and 

2 - Change the HTTP Page Skin to Plain HTML, from the drop down list.

Step 5:

Scroll to the bottom of the configuration page and click on Deploy new configuration.

Step 6:

Wait for the Settings Push to finish.

Step 7:

Once the deployment finishes, you can follow the normal steps to uploading a custom webroot to your Canary.

You're done! ;-)