Premise: Unable to display Facebook posts. Show error Error: Error validating access token: Session has expired on Saturday, 17-Nov-18 06:28:03 PST. The current time is Wednesday, 13-Feb-19 12:29:17 PST.Type: OAuthExceptionCode: 190Subcode: 463Please refer to our Error Message Reference
Hypothesis: PST is the standard time used for error messages.