Thanks, logged as bugs://81534, for the broken CC for Fill
To be creal, the errors is fixed and the code is valid and compiles again, but after closing VS and restarting it, the designer STILL fails? that isn very odd, but we’ll investigate.
Of coursed its comletely expected that the designer fails while the code is broken. Don’t mess with that code.
But I already restore the code from back up 
This scenario usually happen when I want to do repetitive task (in this case I try to make a calculator, I need to handle around 30 buttons).
Editing designer code is faster for me rather than clicking on design view.
Before I play with the code I encounter design error when playing with margin/padding on docked tablelayoutpanel.
I can not fix it.
So I decide to create new project and edit from code.
But I don’t remember the exact step to reproduce
bugs://81513 got closed with status fixed.
bugs://81534 got closed with status fixed.