I has this error two times already. Only cure was to create a new project and using copy&paste filling it with the original code and layout.
I have found that when I have been running Creator 4 for some time especially with a large build and some sleep sessions on a PC laptop that I will get to a stage that when rewiring a schematic that I get a whole lot of errors that will not go away.
I have found that if I save the project, close Creator and then restart Creator and open the project again that the errors have disappeared.
This tends to make me think that there is a memory leak in Creator 4 ?
Never had this with earlier versions of Creator but my projects were a lot smaller smaller at that time.