Disappearing Datasets in Visual Studio .Net 2003

[Patrick]

When I open forms in my project which contain a typed-dataset dropped
onto the form (in the component tray), the dataset will often disappear
from the component tray and be removed from the designer-generated
code.

I am also having problems adding newly-created datasets to a form.
This results in:

"Could not add an instance of [dataset type] to the designer. To
resolve this problem, build the project, fix any errors, and add the
instance to the designer again."

Unfortunately, there are no errors, and the project builds fine. This
doesn't solve the issue.

I hooked up a separate instance of Visual Studio and attempted to see
if any exceptions were being thrown when this form was opened. Here's
what I got.

A first chance exception of type 'System.MissingMethodException'
occurred in mscorlib.dll
Additional information: Attempted to access a missing member.

A first chance exception of type
'System.ComponentModel.Design.Serialization.CodeDomSerializerException'
occurred in system.design.dll
Additional information: The variable 'dsDetail' is either undeclared or
was never assigned.

Any ideas??

 

[Patrick]

As a follow-up to my own post, in case anyone else runs into this...

I solved this by removing the obj folder from within Visual Studio's
Solution Explorer ("show all files" first), then rebuilding and
re-opening the form.

It's fixed, at least for now.