I have an environment where I get an unexpected error when attempting to modify
the CQWP. It is happening across the entire web application. It was working
and then started this and then started working properly and now is not working
again.
Users that are not owners or site collection owners cannot see the web part, it
generates the following error for them: "Unable to display this Web Part. To
troubleshoot the problem, open this Web page in a Windows SharePoint
Services-compatible HTML editor such as Microsoft Office SharePoint Designer. If
the problem persists, contact your Web server administrator."
Opening the page in SPD doesn't change the message...still returns an
"unexpected error" on the page when trying to modify the web part.