Problem with lottie animation

You haven't provided any information to help us troubleshoot, like what your animation is, screenshots, or what, exactly, is missing. 

Without any additional information my first guess would be that you are trying to use raster effects or any other techniques that aren't supported by lottie. If you want a true vector animation, you can't use every tool After Effects has to offer—there are a lot of limitations in what is supported and what isn't. Many expressions are supported, but some need to be baked to keyframes. 

Please provide a lot more information so we can help you out. The most useful thing would be a screen recording of what your animation looks like in AE and then what the lottie animation looks like.