Why did a white screen appear when editing pages and posts in WordPress and how to remove it?

Question

WordPress

Hello. Tell me, please, after updating WordPress, I can’t enter the page and post editor (white screen).
Disabled all plugins one by one, and after disabling Toolset Types the editor opened, but this plugin is the main one and when it is disabled, a lot of information is lost. Its update is paid, will it fix the error? Or are there other ways?

Here is the debug report:
Strict Standards: Declaration of mainMenuWalker::start_el() should be compatible with Walker_Nav_Menu::start_el(&$output, $item, $depth = 0, $args = NULL, $id = 0) in /home/ optmark/optmax.com.ua/www/wp-content/themes/optmaxtheme/functions.php on line 49

Deprecated: The add_custom_image_header function is deprecated as of version 3.4.0! Use add_theme_support( 'custom-header', $args ). in /home/optmark/optmax.com.ua/www/wp-includes/functions.php on line 4714

Deprecated: The has_cap function was called with an argument deprecated as of version 2.0.0! The use of levels for users is deprecated. Use the features.. in /home/optmark/optmax.com.ua/www/wp-includes/functions.php on line 4998

Deprecated: The has_cap function was called with an argument deprecated as of version 2.0.0! The use of levels for users is deprecated. Use the features.. in /home/optmark/optmax.com.ua/www/wp-includes/functions.php on line 4998

Deprecated: The has_cap function was called with an argument deprecated as of version 2.0.0! The use of levels for users is deprecated. Use the features.. in /home/optmark/optmax.com.ua/www/wp-includes/functions.php on line 4998  

Can you suggest a solution to the problem?  

Answer 1

The fact that you have warnings in debugging, they don’t bring down the site, they just need to be corrected
But

after disabling Toolset Types the editor opened

Accordingly, he brings down, update