Whay i got this when i try to update module freepbx framework?

WHAY I GOT THIS WHEN I TRY TO UPDATE MODULE FREEPBX FRAMEWORK ?

Downloading framework 2723771 of 2723771 (100%)
Untarring… Done.
error copying framework files:
‘cp -rf’ from src: ‘/var/www/html/admin/modules/framework/htdocs/*’ to dst: ‘/var/www/html’…details follow
cp: cannot remove /var/www/html/_asterisk/animlogo.gif': Permission denied cp: cannot remove/var/www/html/_asterisk/vmail.css’: Permission denied
cp: cannot remove /var/www/html/_asterisk/play.gif': Permission denied cp: cannot create regular file/var/www/html/robots.txt’: Permission denied
Checking for upgrades…1 found
Upgrading to 2.8.0rc1…
-> Running PHP script /var/www/html/admin/modules/framework/upgrades//2.8.0rc1/custom-context.php
Upgrading to 2.8.0rc1…OK
framework installed successfully


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