This issue also on Ubuntu 16.04 LTS servers (which, BTW, keeps geting security updates for PHP 7.0).
You should use a secure ftp connection (sftp) with only your IP white listed for that task.
Check if the web server has write permissions in the wp-content/plugins, the wp-content/upgrade and the wp-content/themes folders although I wouldn’t recommend installing this way due to the above global write permission.
If you upload your local database to your production site you’ll override everything there.
If the changes you make is in the code, than it should be ok to upload to production.
Try to check the settings on your lightbox plugin
