Ligatures Not working in random areas no matter what I do

[Victoria27774057s2vt]

I'm trying to activate "fi" ligatures in a text box in the spots where they're not working even though they are working in some areas within the same text box (same font, same size, same metrics, same everything) Even copying and pasting the ligature from a spot where it's working. PLEASE HELP!!!! 

[Willi Adelberger]

1. Does the used font support ligatures.
2. Does a character style hunder ligatures?
3. Did you set up ligatures in the paragraph style?

[Joel Cherney]

How sure are you that all of the "same everything" is actually the same? Because the topmost "selfishness" looks tracked out, while the bottom one does not. Sufficient tracking will break that ligature:

You can do the same thing with letterspacing in the Justification window:

That's my guess; there must be some setting that you're missing. If you can't find it, you can post a sample .indd with the broken ligature. I'm sure that we can figure out exactly which setting is causing it. .

[Victoria27774057s2vt]

It could of been a tracking issue. I ended up having to change the font-size for another reason which resolved the issue. Next time I'll check the tracking 

[Joel Cherney]

Sure, it could have been tracking. Don't neglect the Justification panel, though. Your screenshot was too cropped for me to be sure, but I'd be willing to bet that your paragraphs are fully justified. If so, the Justification panel will let you set the amount of acceptable variation of spacing between words, the amount of spacing between letters, and the width of glyphs. It's far more likely that your Full Justification setting that is causing this, and not tracking that you (or someone else?) applied and then forgot about.