Upgrading to the latest version (7.7.0?) failed. Stuck in mainenance.

[gravel]

After running the builtin auto updater I received a message that the upgrade failed. I believe the message said to check logs and try again later. When I clicked the "Finish" button I was brought to a page that said the site is under maintenance. I backed up the WHMCS directory and attempted a few things that did not work. When I restored the backup directory, I'm now getting a 404 error. Suggestions on moving forward?

PHP Info: 7.2 with 128M memory limit.

[gravel]

After restoring again, with `rsync` instead of `cp`, I'm back to getting the maintenance message, even when attempting to login as admin.

[gravel]

Thanks for the info. I was able to restore my old database and put the old files back in  my WHMCS directory. Everything is running again. I'm going to wait for the next release with patches for 7.7.0 before upgrading again. I'll likely do it manually as you suggested.