Please check this benchmark : https://www.techempower.com/benchmarks/#section=data-r12&hw=peak&test=fortune
In that page and also other pages Yii always is “Did not complete”! 
Why?
Please check this benchmark : https://www.techempower.com/benchmarks/#section=data-r12&hw=peak&test=fortune
In that page and also other pages Yii always is “Did not complete”!
Why?
Basic Composer error:
Thanks
Is it a problem related to Yii? or is it a composer issue?
It is a Composer issue - and has nothing to do with Yii I guess.
The issue is not new, probably a month or two old.
It is the classic issue: the asset plugin falling out of sync with Composer.