If after updating a theme you got a blank screen or errors, it is because the theme structure has changed.

So if you drop the new files through FTP, some old files can be still there causings bugs.

To fix this, remove all old files from the theme folder and re-upload the new ones. You can also remove the theme and re-install it. You won’t lose any settings or content.

Note that we will not rebuild the theme structure very often, so you shouldn’t have to do that more than one time.

Besides that, most of my themes have a zip upload update system, and in the recent versions, updating through zip upload will remove unnecessary files to avoid this inconvenience.