I tried to upgrade my Moodle site from 3.9.7+ to 3.10.4 / 3.10.4+.
I don't use git, I did it manually. I have upgraded this site many times from version 3.5 to 3.9.7 without a problem. Always manually.
However, now the procedure stops here:
I tried both with 3.10.4 and 3.10.4+.
My VPS specs:
Maybe the PHP setting max_execution_time needs increasing to allow the upgrade to complete. If this is low, for example 60 (1 minute), then try changing it to 300 (5 minutes).
If you change max_execution_time you normally need to restart the service that runs PHP. This service might be called something like httpd, php-fpm or apache2 depending on your server, for example on my CentOS 8 server it's systemctl restart php-fpm to apply changes in php.ini.
Alternatively you can try performing the upgrade using the command line as max_execution_time doesn't apply. On my system this is done with:
$ cd /var/www/moodle
$ sudo -u apache php admin/cli/upgrade.php
