Problem

New Jira Experience is not able to render the Left Sidebar Menu. It shows up like the image below.

Diagnosis

Environment

• This is related to the client's network blocking resources from Jira, to be received by the browser leading it to not being able to render the sidebar. The way this is blocked, under the client's network, changes from case to case (sometimes proxies, firewalls or even GPOs ...).

Diagnostic Steps

• In Chrome, open the development Panel (Instructions Here).
• Go to the "Console tab" under the panel.
• Check for errors in red. You should be seeing errors similar to the ones below:
  
  •  special attention to net::ERR_INSECURE_RESPONSE appearance.
    
    
  •  mentioning Blocked by CORS Policy.

Cause

Assets in the Network Environment blocking Atlassian resources to be loaded, therefore these don't reach end-users browsers and the sidebar does not load.

Resolution

Check every possible blocking asset (firewalls, proxies, ad blocks...) configuration under your network and application domains and IPs whitelisting provided at Atlassian Cloud IP ranges and domains. If the problem persists, contact support.