i had the same problem after upgrading to KryptonSuite 22.214.171.124.
The problem is, that the new KryptonSuite has a new control, the KryptonMessageBox.
It's just a naming conflict.
The solution is to rename the class in my project to KryptonMessageBoxEx
and if you want,
also the classes KryptonMessageBoxExButtons
After that you have to compile the project.
I hope that helps.