Currently code navigation stops working when there is a flaw in the code structure. There are situations, where it's not obvious where this comes from.

It would be pretty helpful to give a hint like a small red indicator in the scrollbar (somwhow Diff-like style) about the position in the package and additionally a waved red underline for the affected code (like in MS Word's spell check). The information should be available to PL/SQL Developer, because there also must be an evaluation for having a working code navigation.

For not getting too much distraction while coding there could be a lag of a few seconds for the display of a code flaw.