/e/ OS update programme crashes (Fairphone 4)

I’d like to update my /e/ OS on Fairphone 4 from 1.14 to the newest (1.17), but every time I try to launch the update programme it crashes. Do you have any advice for me how to fix this problem? As you can see, I forgot to update the OS several times - maybe this is where the problem lies. How can I update step by step (first to 1.15, then to 1.16, then to 1.17)?
Many thanks!

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone

It might help to clear the app cache and storage.
You should find that app in Settings > Apps > System apps (or similar).

Here is the manual from Manoj (adding urs_lesse’s ‘or similar’)