I am trying to create a custom "myEvent" content type similar to the OOB "Event" content type. Mine has just four columns, Title (default), Start Time (date/time), End Time (date/time), and Description (multiple lines of text). The custom content type was created using a base content type of "Item", and is config'd like the OOB "Event" content type.
I create a calendar list, and add my "myEvent" content type to it. I go to add a new "myEvent" event by picking it from New > New myEvent.
Message: Sys.ArgumentUndefinedException: Value cannot be undefined. Parameter name: id Line: 3098 Char: 12 Code: 0
As a result of the error, the rich text parts for the "Description" column are not rendered, and the column is rendered as a multiple-lines, plain text box instead. So my conjecture is the js error has to do with the rendering of the rich text box.
If I use the OOB "Event" type, no such error is thrown. Googling up "Sys.ArgumentUndefinedException" turns up other instances of this happening, but nothing directly "SharePoint 2010 Custom Content Type". Seems to be related more to other asp.net stuff.
Anyhow, I'm at a loss on what to do to get the custom content type to work. Re-doing the custom content type is easy; it's got very little to it, as this is just the start of a proof-of-concept project. The calendar list to which I'm binding the custom content type is an OOB "Calendar" list, to which I added this custom content type. I'm not doing anything custom jQuery or anything, the whole thing takes minutes to type up from scratch, and should "just work", but does not. Ideas?