Impreza - problem (error 500)


I have a problem with a website where I use Impreza theme.
Since a few days, I have a page with an error 500. In the wp-config.php file, I put the debug on true to see the error and I have the following error

Notice: Undefined index: styling in /home/lengelecca/www/wp-content/themes/Impreza/config/theme-options.php on line 25

Catchable fatal error: Argument 1 passed to us_array_merge_insert() must be of the type array, null given, called in /home/lengelecca/www/wp-content/themes/Impreza/config/theme-options.php on line 71 and defined in /home/lengelecca/www/wp-content/themes/Impreza/framework/functions/helpers.php on line 378

If someone can help me because I don’t know what to do.

The website works very well since September 2015.

Maybe it’s since the last update of the theme. I don’t know really.

This forum is not for items support, you need to contact theme author via the Support panel for the theme.