Steps to Reproduce:

1. Occurs for users with Opt-in for new side bar feature.
2. Access Agile Board.
3. Also Effected by Bug: https://jira.atlassian.com/browse/GHS-11672
4. Cannot navigate away from overview of a single project using Project Drop-down navigation menu.

Info for Atlassian
Have com.atlassian.jira.projects.ProjectCentricNavigation.Switch or com.atlassian.jira.projects.ProjectCentricNavigation dark feature activated.

Diagnosis

• Launch JavaScript console
• You will see the following error generated when trying to navigate to new project (See Screenshot):

  GET http://<YOUR INSTANCE NAME>.atlassian.net/rest/greenhopper/1.0/rapidviewconfig/editmodel?rapidViewID=unified& =<Some Number Set> 404 (not Found)
  

Resolution:

• File A support Request at https://support.atlassian.com
• we will need to schedule a restart of your service.