To resolve above error login into your server with root login details and follow the following steps.

1) First found out the owner for your domain where you have seems the “403 Forbidden error” and once you found out the user name for your domain then fire the following command one by one touch /home/username/public_html/_vti_bin/_vti_aut/author.exe or touch ~username/public_html/_vti_bin/_vti_aut/author.exe chown username.username ~username/public_html/_vti_bin/_vti_aut/author.ex chmod 644 ~username/public_html/_vti_bin/_vti_aut/author.ex If you are having Frontpage problem with the addon domain then change the path as per your addon domain document root path and create a author.ex file under your addon domain.Then try to publish your site by using Frontpage