Steps to (sometimes) reproduce:

• log into Cloud with your default browser,
• click a link to an OnDemand instance (e.g. from a JIRA notification email) from a third-party application (e.g. email client),
• the link will open in the browser that already has a current session in that Cloud instance, yet will prompt you to login.

The third-party applications that have been involved in reported cases include:

• MS Outlook
• MS OneNote
• MS Word

Workaround

With the registry change in place, no requests emanate from the office apps: they are handed over to IE immediately. This should prevent the redirection to the login page, and could therefore be a suitable workaround for customers suffering from this problem.

The registry change consists of setting or creating a DWORD key ForceShellExecute with value 1 under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\9.0\Common\Internet.