Class name must be a valid object or a string error

error on this function line 224

/var/www/cportal/data/www/mysite.com/vendor/laravel/nova/src/Nova.php

    public static function availableResources(Request $request)
    {
        return collect(static::$resources)->filter(function ($resource) use ($request) {
            return $resource::authorizedToViewAny($request) &&
                   $resource::availableForNavigation($request);
        })->all();
    }

@atmaboy is it maybe related to this error: https://github.com/laravel/nova-issues/issues/941#issuecomment-451618181

Show the code that throws the error if this is not the case please.

I already wrote there, 15 days without reply

https://github.com/laravel/nova-issues/issues/2240

i have this error with clean resources on fresh install

@atmaboy what are the steps that you take afterwards, as I've just tried fresh install on Nova, the same versions as you did, and all seems correct so far?

reinstall everything, and now it works...

how did you reinstall everything? I am installing via composer I removed the nova directory and reinstalled it via composer and I have the same error. The error started after composer update to v2.9.3

composer remove laravel/nova
composer require laravel/nova
php artisan nova:publish

error persists.

i had to downgrade nova to 2.6.* for it to work... FYI, I had no problem running it locally, but I get this problem when hosting on a DigitalOcean droplet. PHP versions are identical

@jhchong Thats the same thing for me working on local but not on production. Downgrading to 2.6.* worked. I am running the same version of php 7.2 on both machines (maybe different configurations?). I'm running a older version of laravel 5.8.

I'm having the same issue , the thing is i'm having the issue only for some resources other resources are working just fine , i have php version 7.1.3 and an older version of laravel 5.8 , should i downgrade nova to 2.6.* ?

I was having the same issue while upgrading to any version above 2.6

My issue was cached config file that was missing the new nova.actions.resource

(https://github.com/laravel/nova-issues/issues/2849#issuecomment-691230624)

this also explains why some were having issues in one environment but not in another