Hi,
We are seeing this issue more recently with Windows update of following build.
Since then, please test by removing the windows update installed recently. And if the issue disappears, it might be the conflict between the patch and the applet, for which, you would wait for next update in the following months.
But if the issue persist, then you could contact the support of applet vendor or discuss code used in the corresponding developer forum.
https://social.msdn.microsoft.com/Forums/vstudio/en-US/home?forum=csharpgeneral&filter=alltypes&sort=firstpostdesc
Hope this helps and please help to accept as Answer if the response is useful.
Thanks,
Jenny