Search by People in SharePoint 2010 generates:
Unable to display this Web Part. To troubleshoot the problem, open this Web page in a Microsoft SharePoint Foundation-compatible HTML editor such as Microsoft SharePoint Designer. If the problem persists, contact your Web server administrator.
Switching to "All Sites" under search returns results. I can open the site in SharePoint Designer but not sure where to go from there.
Site: /sites/Search/Pages/peopleresults.aspx
I removed and added People Search Core Results it causes the same issue.
Any thoughts on how to resolve this issue?
UPDATE: The issue appears to have started after installing the December SharePoint updates.