https://forum.ait-pro.com/forums/topic/read-me-first-pro/#root-htaccess-file-lock
IPage hosting does not allow locking the root .htaccess file with Read-Only 404 file permissions.
403 Forbidden Error or 500 Internal Server Error when updating/upgrading BPS
Some web hosts (approximately 6 Hosts out of 1000’s of Hosts) have a strict policy that .htaccess files can ONLY have 644 permissions and do not allow you to change your .htaccess file permissions to 404. During the BPS automatic update/upgrade process your Server API is detected and if it is a typical SAPI that should allow your .htaccess file to be locked with 404 permissions then BPS will automatically lock the file. To see if this is the problem that is occuring FTP to your website and change the .htaccess file permissions in your website root folder to 644. If the 403 error goes away then please let us know which Host you have by posting a comment here so that we can add them to the below of Hosts that do not allow 404 file permissions for .htaccess files.
If your Web Host does not allow locking of your Root .htaccess file (404 file permissions for your Root .htacces file) and your site has crashed then FTP to your website and manually change the root .htaccess file permissions to 444. If your site is still crashed/not loading then change the root .htaccess file permissions to 644. After your site is back up go to the BPS htaccess File Editor tab page and click on the Turn Off AutoLock button. This will prevent your Root .htaccess file from being automatically locked when you upgrade BPS, which will prevent a 403 Error from occurring on your website.
List of Web Hosts that require 644 .htaccess file permissions – 404 permissions are not allowed on these Hosts and will cause a 403 Error and or a 500 Internal Server Error – 444 file permissions may be allowed
webmasters.com
LiquidWeb.com
iPower
iPage
Fatcow
Strato
