Inbox Personal Messages Gone

[Bob]

  It seems newer board format has wiped out all my inbox messages.The
  sent ones are still there.

[Prospector Bob]

All my inbox messages are gone as well. I wonder if there's a time limit before they are automatically cleared? Oh, yeah, my sent messages are still present too.

[Gus]

My in box has only two messages; both this July. My sent messages all seem to be there since 2013.