This is fairly common with Visual Studio, but nothing critical. It's just something it does when working with source code components.
Sometimes you can clear it up by simply closing the design view of the form, rebuilding the project, then reopening the form from the Solution Explorer. If that doesn't fix it, try this:
1) Close the form designer window
2) Save the project and close Visual Studio
3) Browse to your project with Windows Explorer to the \AdvancedHMI directory
4) Delete both \bin and \obj directories (these are built from source code, so you won't lose anything)
5) Open the Solution and Rebuild
6) Open the form in design view
