Lumen/Laravel 6: Call to undefined function array_except()

All str_ and array_ helpers have been moved to the new laravel/helpers Composer package and removed from the framework in the new version (6.0)

You can add helpers' package:

composer require laravel/helpers

as I see you added the package try dump-autoload:

composer dump-autoload

Upgrade 6.0 - String & Array Helpers Package

Bit late to the party but:

as others have mentioned str_ and array_ helpers have been moved to a seperate package. If you don't wish to use that package after updating to laravel 6 you have to clear the views that were compiled using the old helper methods.

composer dump-autoload

then

php artisan view:clear

worked for me

Ok, after @aynber suggested grep'ing everywhere, I've found that some of the views in storage/framework/views had the line array_except. After deleting everything within that directory and regenerating autoload.php as suggested by @sharhabphp it all worked fine again.

Thanks everyone!