Web Part Error: A Web Part or Web Form Control on this Page cannot be displayed or imported. The type could not be found or it is not registered as safe.
After upgrading Test Environment - MOSS 2007 SP1 to SP2 + all latest Cumulative Updates, I am getting the above errors for individual site's main page as I think it's customised in xml format with the following header:
<?xml version="1.0" encoding="utf-8"?><DocLibTree>
Adding ?contents=1 to one of the test site, I can see the following:
Webpart Title Type Open on Page?
Error ErrorWebPart Yes
Checking on production site:
Document Library Index DocLibIndexWebPart Yes
What do I need to do in order to fix this? Please note the test environment is an exact duplicate of our prod environment which was created last month. So should I assume the webconfig should be the same as the production environment?