Failed Upgrade To 4.10.4

I've tried to upgrade CS-Cart from 4.10.3.SP1 to 4.10.4 with the upgrade process in Admin.

I got a list of file writing permissions that must be modified, and I set them with chmod.

After this, the upgrade process check permissions again for more than an hour.

Now, I could not access to admin, I get a 404 error, and If I try to access to the store I get this error:

Smarty: Unable to load template tygh 'index.tpl' -->

Please, could it be possible to complete the upgrade manually, or to get back to the previous version?

Please make sure that the following file exists and has correct permissions

design/themes/THEME/templates/index.tpl

Hello, eComLabs

Thanks a lot for your answer. Finally we had deleted the previous version and install the new one, it was not possible to fix it.