Hallo, 

Frontend is everything fine.

I have blanc screen after update (only BACKEND ) and this error:

I have tried to update automatic im Backend. And error apears. 
Then i have tried to update manual via FTP. Same problem.

Notice: Undefined property: stdClass::$kalium_url in /pages/aa/37/d0013559/home/htdocs/test/shop/wp-content/themes/kalium/inc/classes/kalium-main.php on line 129

Fatal error: Uncaught Error: Call to a member function get() on null in /pages/aa/37/d0013559/home/htdocs/test/shop/wp-content/themes/kalium/inc/classes/core/kalium-theme-upgrader.php:46
Stack trace:
#0 /pages/aa/37/d0013559/home/htdocs/test/shop/wp-content/themes/kalium/inc/classes/kalium-main.php(176): Kalium_Theme_Upgrader->__construct(Object(Kalium))
#1 /pages/aa/37/d0013559/home/htdocs/test/shop/wp-content/themes/kalium/functions.php(19): Kalium::instance()
#2 /pages/aa/37/d0013559/home/htdocs/test/shop/wp-settings.php(426): include('/pages/aa/37/d0...')
#3 /pages/aa/37/d0013559/home/htdocs/test/shop/wp-config.php(119): require_once('/pages/aa/37/d0...')
#4 /pages/aa/37/d0013559/home/htdocs/test/shop/wp-load.php(37): require_once('/pages/aa/37/d0...')
#5 /pages/aa/37/d0013559/home/htdocs/test/shop/wp-admin/admin.php(31): require_once('/pages/aa/37/d0...')
#6 {main} thrown in /pages/aa/37/d0013559/home/htdocs/test/shop/wp-content/themes/kalium/inc/classes/core/kalium-theme-upgrader.php on line 46

This works. Thanks! 

>>@Lafac

>>Please try the last one I have posted:

>>Download this file and replace it in this directory (of the theme): /wp-content/themes/kalium/inc/classes

>>@jdgranja Great!

>>Kind regards, Arlind