Argument 2 passed to Cartalyst\Sentinel\Permissions\Standard Permissions::prepare Permissions() must be of the type array, null given

I have a Laravel 5.3 project with the Cartalyst\Sentinel (v2.0.15) package configured. I have this line

$hasPermission = Sentinel::getUser()->hasAccess($routeName);

But I keep getting this error message:

Argument 2 passed to 
Cartalyst\Sentinel\Permissions\StandardPermissions::prepare Permissions() must be of the type array, null given

I had a look on Google and the package's github page but couldn't find anything that would help me to solve this problem.

When I look in the source code of the package then I see this piece of code:

/**
 * {@inheritDoc}
 */
protected function createPreparedPermissions()
{
    $prepared = [];

    // $this->secondaryPermissions equals to:
    // [
    //     0 => NULL,
    // ]
    if (! empty($this->secondaryPermissions)) {
        foreach ($this->secondaryPermissions as $permissions) {
            // this is the line where it throws the error as $permissions == NULL
            $this->preparePermissions($prepared, $permissions);
        }
    }

    if (! empty($this->permissions)) {
        $permissions = [];

        $this->preparePermissions($permissions, $this->permissions);

        $prepared = array_merge($prepared, $permissions);
    }

    return $prepared;
}

The secondaryPermissions array isn't empty. What are these 'secondary' permissions? I had a look on Sentinel's documentation page(s) but couldn't find anything about this. The only thing I could find is that a 'user' can have permissions but so does a 'role'. My current database setup is that roles have permissions but none of my users have any specific permissions. So the 'permissions' field in my users table always equals to NULL.

Thanks.

Fixed it. The issue was that the permissions were incorrectly stored in my database.

It should be like:

{"controller.action": true, "controller.actionTwo": true}

Instead of:

{"controller.action: true", "controller.actionTwo: true"}