Symptoms

When browsing Cloud Applications the content is shown but styles are missing. e.g:

Diagnosis

By opening the Chrome Network console (right click + inspect element, then Network) and refreshing the page, the cloudfront URLs are shown in red colour as they are being blocked.

The page renders normally when browsing it from outside the network. Cellphone for example.

Cause

Atlassian Cloud uses CDNs to provide CSS files and those CDN Servers are being blocked.  ID-236 - Getting issue details... STATUS

There are instances where this happens after a site import. If the CDN URLs are not correctly relating to the new instance URL, the CDN URLs will be blocked and will not allow resources to be downloaded.

Resolution

The block might be done by a network firewall or by an antivirus.

If there is a firewall in the network, make sure that all IP address range used by Atlassian Cloud is whitelisted. 

Disable antivirus to check if it is a local problem.