Fatal error after updating Meta Box because of extended class

Hi,

I just updated Meta Box and run into the following error in the admin area:
Fatal error: Uncaught Error: Class 'MBAC\Post' not found in [...]/plugins/dab-admin-columns/PT_Admin_Columns.php:2

In this file I extended my class from MBAC\Post:
class PT_Admin_Columns extends \MBAC\Post {

The cause was that Meta Box was not activated after the update installation. But unfortunately the Admin area doesn't allow me to activate Meta Box (and the extensions) to get my own plugin running.

So first I had to deactivate my class mentioned above in order to access the admin area again - to then finally be able to activate Meta Box again.

Question: What is the correct way to prevent such serious errors?

Thanks!
Juergen