[Dx4win] Canvas does not allow drawing

[ARS NZ3O (Byron) FM29fx]

Msg 'Canvas does not allow drawing'

Q:
What does the error message 'Canvas does not allow drawing' mean?

A:
you may have run out of resources, which means a new DC cannot be
allocated. Usually this is a result of not freeing unused DCs or other
objects
you are attempting to draw to an device context that is not yet valid.
Such as in the create constructor of a component.
you are trying to draw on a canvas while your last draw-operation has
not finished yet. In this case you can use Canvas.Lock or Canvas.TryLock to 
fix it.