All,
Somehow, I have managed to disable ‘variable/ element highlighting’ in Aptana Studio 3.
Online search brought up someone’s advice to enable ‘Highlight current line option in the General > Editors > Text Editors section of the Preferences dialog’, which is already enabled and I think is actually for line highlight, not variable highlight.
Thanks,
Since last release it’s turned off by default, to activate it click on little marker icon on toolbar.
Found answer: Minor Highlighting bugs on Mac, see comments:
If you want it on, you can turn it on by clicking the Hightlight Pen icon in the toolbar == shortcut key Alt–Shift–O on Windows.