Interpreting the info in a Component Exception

I have Gh definition that is consistently throwing up a Component Exception for an Item Selector, of which I have several and scattered.

An Object reference not set to an instance of an object.

" c_POS: {X=7841, Y=11060} "

The information above appears to relate to X and Y co-ordinates on the Canvas, but how to interpret these measures, I wonder in order to fix the selector?

I have a large, sprawling definition …