The first thing to do is to confirm that kerning is turned ON in your application.
1. 1. Highlight a kern pair (example “Si”).
2. 2. Go to your application text preferences or formatting.
3. 3. Confirm that kerning is turned ON. In some cases kerning has been enabled only above certain point sizes.
4. 4. Confirm that there is a kerning value set by opening the font in a Fontlab Ltd. Font editor and displaying the kerning pair in the Metrics window. There should be a percentage shown for the selected pair.