1. I added an effect to my animation but it's not rendered in the app

There are a number of effects in Adobe After Effects that are not supported on certain platforms. When this kind of error happens, it's best to go to the list of supported effects in Lottie's documentation at https://github.com/airbnb/lottie/blob/master/supported-features.md.

Take into account that this list may change over time, as Lottie is being constantly improved. As the list shows, the same effect may show on a specific platform but might be missing on a different one.

The most common approaches for these cases are to remake the animation, remove the selected effect, or create a different animation for the failing platform, as there is no programmatic solution for this problem.