Unable to delete analysis from schematic. Bold black X's on objects
The black X on component indicate that the underlying data is missing - this is usually result of a corrupt project. Such corruption can happen during project-save when certain unexpected error occurs.
Usually user should be able to work with the rest of the project as long as he does not interact with the corrupt system. If he still prefers to delete the system and it doesn't work via context menu, he can try deleting it via command window.
Open the WB command window (file -> scripting -> open command window) and type the following Python script (remember that indentation is critical in Python)
for system in GetAllSystems():
if system.DisplayText == "36 Full Root Radius":