Glad to hear that you were able to resolve the issue.
It is worth noting that if you have permissions or owner conflicts, that may cause issues when uploading files via FTP. I.E. if the file was owned by someone other than the FTP user you're using, it may not upload correctly. Always contact your hosting provider if you are unsure about proper permissions or user/group ownership.
Additionally, once you upload the new files to your server for the new version, the only way to "cancel" the upgrade at that point would be to restore the previous versions files and if the upgrade did any progress past what you have in your screenshot, restore your database. This is why we recommend taking a full backup prior to attempting an upgrade.