This is usually caused by downloading issue. Either there is no network connectivity or it's flaky, the data server is down or the downloaded data is corrupted. Here are some steps you can follow to fix the issue:
- Exit the app using the back arrow or by swiping it out of the list of open apps, then open the app again.
- Check your network is connected
- In the top right menu, select "Refresh" and force a complete download it the option dialog is shown.
- Clear the app data via the Android Settings > Apps > Flowx screen.