Problem with css and js minification in Yii2, why?

Question

css

When I try to minify my assets, it says "Class app\assets\MainAsset does not exist".
Nevertheless, yii assets (yii\web\YiiAsset, yii\web\JqueryAsset) sees, compresses, everything is ok.
Any ideas?

Answer 1

of course there are ideas. You have written app\assets\MainAsset somewhere, but actually not. The rest of the assets are there and they are compressed. That's really all that can be said for the information.