Ran into an error while upgrading. The error occurred during migrate step, when attempting to apply patches. I had to use the following command just to pass the step, although it is not recommended for production:
bench --site {site} migrate --skip-failing
See snapshots by following the link below:
https://1drv.ms/f/c/f63322d8e0915923/EkcpgJLNls1KgYtbWejeOzYB8szcWqT5a_3RPuxOKsSoQA?e=9rPEDe