Symptoms

No startup messages or any content appears in the atlassian-confluence.log, usually during an upgrade attempt, restart, or some other configuration change. 

Diagnosis

Check the permissions on both the confluence-home and confluence-install directories. On a Linux system, use "ls -al".

Cause

Permissions are insufficient for the user who is running Confluence to write to the confluence-home directory.

Resolution

Apply the appropriate ownership or permissions to the confluence home directory. Something similar to:

chown -R confluenceuser:confluenceuser confluence-home

substitute 'confluenceuser' with the name of the correct user, and 'confluence-home' with the name of your home directory.