Is it ok to take whey protein drinks when you have fatty liver disease?

Yes: I'm going to assume that the cause has been identified as metabolic syndrome or recovering from alcohol abuse. This is very good idea as a (maybe the) mainstay of your recovery should be aerobic fitness.

Whey protein: It is safe to take proteins with fatty liver. If you are obese and qualify for weight loss surgery then you should consult a bariatric surgeon. If you already had surgery whey proteins are part of a post bariatric diet.