Interface 'Assetic\Filter\FilterInterface' not found

[losttheplot]

Hi. Thanks for publishing this. I'm getting an error on installation, the result of which is that the Design > Theme > Customise interface is blank...

From the website: "Interface 'Assetic\Filter\FilterInterface' not found"

From the logs: "PHP Fatal error: Interface 'Assetic\Filter\FilterInterface' not found in [hidden]/html/packages/asset_pipeline/src/Asset/Filter/Assetic/JShrinkFilter.php on line 14"

Line 14 of JShrinkFilter.php starts:

class JShrinkFilter implements FilterInterface
{
    /**
     * {@inheritDoc}
     */
    public function filterLoad(AssetInterface $asset)
    {
    }
    /**
     * {@inheritDoc}
     */
    public function filterDump(AssetInterface $asset)
    {
        $asset->setContent(\JShrink\Minifier::minify($asset->getContent()));
    }
}

I can confirm that /vendor/kriswallsmith/assetic/src/Assetic/Filter/FilterInterface.php is in place, with suitable ownership and permissions.

Any ideas as to what the problem might be please?

[Kaapiii]

I faced the same issue. In the install method of package controller class the following line needs to be called.

$this->loadDependencies();