What if I have problems upgrading the plugin?

Before you perform any upgrades, test your changes in a staging/testing environment -- Never (ever) make major changes to your production environment without testing them first. Do not assume that your custom environment is compatible with a new software package.

If you have upgraded your production environment without testing your changes first, please revert your site immediately! 

Do not try to resolve new issues and bugs in your production environment. Instead, revert your production site to a stable configuration. You can then resolve any issues and bugs in a staging environment.