Hi FredHeida,
How did you use the sample and make your own designer?
I have used that sampe and did not get any error message or question message when I drag a control on to the form.
You can add some break point at the code you have modified, then run your application to see where the error occurred. If you have any problem to do so, please send me the project (v-kiqian@microsoft.com)
Please inform me the test result.
Sincerely,
Kira Qian
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