For working with Liza Pro, it is necessary to have contextual alternates activated. Never heard about this stuff before? No worries. In most programs this is on by default. Only in some older programs, you have to activate this manually. You can easily check this, with typing ohohoh (set in Liza Display Pro, don’t add spaces between ohohoh). Contextual alternates are activated if all 3 oh’s are different. If not, please select your program in the overview below to see how to activate it.

Creative Suite 5/4, Illustrator
Illustrator 5: Contextual Alternates and Ligatures are on by default.
Illustrator 4: Contextual Alternates are not activated by default, although the OpenType palette shows that they are acitvated. This is a bug of the program (only in Illustrator CS4). You have to deactivate and activate them again to make Contextual Alternates work. This bug is most likely to be fixed in the next update.

Control features in the OpenType palette: Window > Type > OpenType