Debugger Error:Invalid scope kind

I have a type called TPath. Path contains a list of type Tballs (the list is called ballList)

Previouspath, currentPath and NextPath are all instances of TPath - therefore each containing lists ballList.

PreviousPathLink, currentPathLink and nextpathLink are all links to the first ball in their ballList. (previouspathLink points to previouspath.ballist, nextpathLink points to nexpath.ballist etc).