Thumbnails are not generated

Omeka S installed and running ok, except with thumbnails. ImageMagick is installed and running, the path to it is /usr/bin.
When I upload a media file, the file is saved in files/original folder, but thumbnails are not generated. For this issue I’m geting an error log of this kind:

2017-12-29T20:44:57+00:00 ERR (3): Command “/usr/bin/convert ‘/tmp/omekaKMczko[0]’ -background white +repage -alpha remove -thumbnail ‘800x800>’ ‘/tmp/omekabUKNae.jpg’” failed with status code 1.

Any idea what could be causing this issue?

What version of ImageMagick do you have?

I was having a look to the configuration options on the Omeka S user manual.
This might have something to do with the paths.
My local.config.php file have the default settings:

'service_manager' => [
    'aliases' => [
        'Omeka\File\Store' => 'Omeka\File\Store\Local',
        'Omeka\File\Thumbnailer' => 'Omeka\File\Thumbnailer\ImageMagick',

What should I change for?

I tried:

        'Omeka\File\Thumbnailer' => '/usr/bin',

But I get an error.

With Omeka Classic installation the path /usr/bin for imagick works fine.

I got it!

I changed my local.config.php file settings from:

    'Omeka\File\Thumbnailer' => 'Omeka\File\Thumbnailer\ImageMagick',


    'Omeka\File\Thumbnailer' => 'Omeka\File\Thumbnailer\Imagick',