"Message inaccessible due to invalid credentials, please re-login from web application and try again" why filing an email from the FYI drawer in Outlook

Issue
When I try to file an email from the FYI drawer in Outlook I see the following error message in drawer

"Message inaccessible due to invalid credentials, please re-login from web application and try again"

Cause
You are logged in to the FYI Add-in to a different account to that of the recipient of the email. It is likely you are using two different email addresses.

Due to Microsoft limitations, you cannot use the Add-in technology that FYI relies on for AutoFile. Refer to the Microsoft article Create a shared mailbox.

Solution
You can create a separate Outlook profile for the email address.
or
Open the shared mailbox from the web version of Outlook to use the full potential of the FYI Add-in. Refer to How can I use a Shared Mailbox?.