Problem:

Getting, "This page can't be displayed" when opening modal Dialogs (Create new Template, Save Template etc.)

Possible Reasons:

It normally happens when the security level for the trusted sites is set to low, medium-low and medium. Internet Explorer avoids in this case that the content from IFrame is loaded.

Solution:

You have to add the app url from Collaboration Manager 365 and the tenant url to the trusted sites from Internet Explorer.

Needed Information:

• App url:  https://cm365prodv2.azurewebsites.net/
  
• Tenant url:  https://s2sshowcase.sharepoint.com – Replace "s2sshowcase" with the name of your tenant.
  

Adding these URLs to the trusted sites:

1. Open the "Internet options", then click the "Security" tab:

2. Select "Trusted sites" and click "Sites":

3. Enter the URLs and click "Add". Please add both URLs: 

To finalize close and reopen the browser. You should now be able to use our modal Dialogs.