I have found a solution to this problem, and it’s pretty simple.

All you need to do is go into your old update’s file. If you’ve played the game and saved, the saves should show up in the first folder. Download the new version, and copy/cut your old save file into the new folder in the same place. If you load up the new version, the save should be just where you left it, but in a new version.

You may not have all the things you may get from the new update however. For example, if a new Ultimate was added to be unlocked at LVL 10, and your old character is already LVL 10+, it won’t learn the Ultimate. This is a minor issue, so it shouldn’t affect any one too much. Be sure to let me know how it works :D