MobilePress plugin and WordPress 4.1 update

I’m going to be short:

  1. Be up to date is very important. There are a lot of reasons but my “favourite” is security.
  2. Make a backup before update, so you can restore the site if something was wrong.
  3. What can be broken and how could it be fixed? I can not know, I’ve never used that plugin and I’m not going to test it for you (sorry, test and fix third party software is not the purpose of this site), but I can advise you to do this: make a mirror site with the exact same set of themes and plugins. Working in the mirror site, enable WP_DEBUG to know if you are using deprecated stuff that can break WordPress in the future. Fix errors if any. Then update. If everything is fine, you are ready to update the live site.