Loss of use of message flagging feature

[e.seaman]

Question:
How can I regain the ability to flag a highlighted message that I
received? When I click on the flag in the toolbar, it does not flag
the message.

Also, the flag icon no longer appears next to the attachment icon,
below the "From" and under the "Inbox."

 

[Mickey Stevens]

Go to View > Columns > Message Status to show the flags.