I’m building a web part with the user control technique. My user control contains a few public properties that need to be set by the web part (the user control consumes a web service and the properties include proxy server info [if needed] and web service URL info). I have implemented a custom toolpart that displays a few properties to be filled in, and it saves the properties in non browse-able public properties on the web part.

My problem is when I click APPLY or OK in my toolpart. I get an error at the top of the toolpart stating the following:

“One or more errors have occurred. See below for details.”

But nothing is shown in my web part toolpart that indicates any errors, it just didn’t work. I’ve stepped through all my code (ApplyChanges, RenderToolPart, etc) but I get all the way to the last RenderControl in the RenderToolPart and it throws that error above… but nothing when I try to catch it with a try-catch block.

Any idea what’s going on? I don’t think it has anything to do with my user control as I’ve commented all code that sets the properties.