JS/CSS aggregation not creating css folder I am creating a Drupal 8 website with a custom theme. 
When css and js aggregation checkboxes are checked, js directory is created in sites/default/files/, however css folder does not get created.

Also all js and css is not working.

When I ran this command in terminal ls -l sites/default/ I get the following line for files folder 

drwxrwxrwx  7 admin  staff    224 May 10 10:30 files

Would there be any reason the site does not create css folder in sites/default/files?

Thanks in advance.
I believe this issue is due to incorrect permission. Can you check the permission on the folders. It will also be helpful if you print the related error/warning/notice logs with the question.

Thanks