Illegal offset type in isset or empty installing yii2-jui

After running

composer.phar -vvv require --prefer-dist yiisoft/yii2-jui

I get the following error:

Composer version: [color="#000080"]Composer version 1.0-dev (e8abc90b923250527a2d68712b663f0f41790594) 2016-03-09 11:44:27[/color]

What can I do to install yii2-jui? I’ve already deleted the composer cache directory, tried with a new Yii2 installation with no success…

There is an issue in Composer since the last version.

Try to force the assets plugin to update


$ composer global require fxp/composer-asset-plugin:dev-master --no-plugins

then update your project.

The fix worked for me, at least, hope it helps.

Thank you. It worked for me as well.