EDIT 2 - 23. January, 2021 10:55 (UTC+0):
We now fixed the issue in game version 34.0.2, which should be available soon on both platforms.

If you have any issues updating the game or do not have the version available yet, please consult the following help articles:

EDIT 1 - 23. January, 2021 7:54 (UTC+0) (Edited for clarity 8:46 (UTC+0)):
We are currently working on a fix for the crashes players are experiencing when trying to access the Mythic Titan, however, this may take some time. In the meantime, we ask players to try the following steps to work around the issue:

1. Go into the Map view. Choose any map level. (e.g. Season 1, Province 1, Stage 1)
2. Select your Team 1 for battle. (The first team in your roster, you will need to swipe all the way to left, to your first team).
3. Enter the battle (and either flee or complete it).
4. When the battle is over, the Mythic Titan battle should be accessible and you should be able to edit your team.
5. You may need to repeat these steps if you use a different team in story missions between Mythic Titan Battles.

Please see video below for the steps:

Thank you for your patience while we investigate this and please accept our apologies for any inconvenience.

We are currently investigating the crashes that happen when attacking Mythic Titans.

We will update more information here soon.