Error installing extensions

[chuong_lam]

Hi everyone,

I got this error when installing an extension. Can anyone help?

$ php -f bin/magento setup:static-content:deploy -f

The contents from the "/var/www/htdocs/magenton7/pub/static/frontend/Magento/luma/en_US/mage/calendar.css" file can  
  't be read. Warning!file_get_contents(/var/www/htdocs/magenton7/pub/static/frontend/Magento/luma/en_US/mage/calenda  
  r.css): failed to open stream: No such file or directory   

I see the calendar.css in the folder.

[theMageComp]

Hello @chuong_lam 

Make sure the folder permissions

find ./vendor -type d -exec chmod 775 {} \; && find ./app/etc -type d -exec chmod 775 {} \;
find ./vendor/* -type f -exec chmod 664 {} \;

Try giving 777 permission to 

find ./var -type d -exec chmod 777 {} \;
find ./pub/media -type d -exec chmod 777 {} \;
find ./pub/static -type d -exec chmod 777 {} \;