SharePoint 2010 Web Part Page has a web part list view on it that displays a list in the site. It has worked for several years no problem. Suddenly today it won't display and says:
"Unable to display this Web Part. To troubleshoot the problem, open this Web Page is a Microsoft SharePoint Foundation-compatible HTML editor such as Microsoft SharePoint Designer. If the problem persists, contact your web server administrator.
I open the page in the Designer and it renders find. But, if I then click on Preview in Browser from the designer it fails with the same message.
Any suggestions on this would be greatly appreciated.