Is this resolved? It seems you have some composer settings or connectivity issues.
I have no problems with Composer but couldn’t install your extensions either. Please see this post.
The same thing happens with other people’s Yii2 extensions.
Seems some problem with your environment and composer settings/connectivity.
Trust this is resolved as in your other issue.
I’ve encountered the same problem. It was caused by the “minimum-stability” field in the composer.json config file.
In Yii2 application template it’s set to “beta”. In order to install some of Kartik’s extensions it has to be set to “dev”.
This is correct - most of my extensions are consistently updated to the latest Yii2 development release and not locked for Yii2 beta. So you must set minimum stability to dev within your composer.json in app root.