By the end of the year, many people want to create the video of their 2018 year. During that time, there might be some cases of heavy load, hence the video generation might take a bit time (up to 1 day).
How to solve it:
1. Wait up to 1 day for the video to be generated. You will receive push alert once it's done.
2. If the video is still not in the Inbox and you didn't get the push, cancel generation and submit again. This would update the process.
Usually, depends on number of flights in your history, it takes around up to 1 hour.