My default.aspx page has four parts.  Everything looks and works as it should.

I added a new part. This part has client-side script that uses the WPSC to read and save a custom property. It does not work. (Here we go again...)

What I've discovered is that the WPSC is using the web services (in this case, GetWebPart) to communicate with the server. The call to this service is failing with a status of 500 - Server error. (Very helpful message, don't you think!!)

So, I attached the debugger to the iexplore process and trapped the SOAP messages. The response the the GetWebPart call is a soap:Fault with an error string of:

A Web Part or Web Form Control on this Web Part Page cannot be displayed or imported because it is not registered on this site as safe.

I found the Web Part Maintenance page, which is located at /_layouts/1033/spcontnt.aspx. This page lists all the web parts on the specified page and allows you to “close” or delete them. Very useful.

In my case, however, all of the custom web parts are listed as Error!!!

So, after four hours, I'm lost.  How in the world can I see the parts if they are not safe?

Help.  Please.