Your store is running Magento 2 and suddently got this error You don’t have permission to access /magento on this server. You may get crazy with Linux folder permission in this case. No worry, there is a simple solution for that.
This error indicates that a default document could not be found at the specified URL and that directory listings are not permitted.
Forbidden You don't have permission to access /magento on this server.
sudo chown -R $USER:$USER /var/www/magento sudo chmod -R 755 /var/www
You can replace correct Magento path
It comes to the end of tutorial: Magento 2 You Don't Have Permission To Access / On This Server.