The blue bar (Chrome Control) at the top of the page is not being displayed and Internet Explorer shows up the notification "Only secure content is displayed".
The Chrome Control loads content from SharePoint and from Collaboration Manager. If secure (https) and non-secure (http) content is being loaded, then Internet Explorer will prevent the non-secure (http) data to be displayed.
For more information see: https://support.microsoft.com/en-us/kb/2625928
You have to tell Internet Explorer to always display mixed content.
1. Open the "Internet options", then click the "Security" tab:
2. With the Internet zone selected, click the Custom Level:
3. In the Settings box, scroll down to the Miscellaneous section, and under "Display mixed content" choose "Enable":
If the problem persists, consider closing and reopening the browser.