Summary

Confluence is missing from the Application Navigator (hamburger menu).

If you look at the Application Navigator configuration, you see that the Confluence link no longer exists there.

Workaround

Users can navigate to https://<yoursite>.atlassian.net/wiki directly.

To fix the missing link, an administrator can:

1. click on the Application Navigator (hamburger menu) and then select configure...
2. click on the refresh icon on the right hand side of the screen, above the table of application links
3. finally, refresh your browser window so the updated menu is loaded