Ok now depending on which host you have the correct RedirectMatch code will be…
either
RedirectMatch 301 ^/index.html$ http://example.com/
or
RedirectMatch 301 ^/add-your-site-root-folder-name-here/index.html$ http://example.com/
…But try this first…
Add this .htaccess code directly above your WordPress Rewrite .htaccess code. This will ONLY work if you have done the other mandatory step for WordPress GWIOD site types, which is to copy your index.php file from your WordPress installation folder and edit it and add your WordPress installation folder name in that index.php file. See the GWIOD link in my previous post for instructions on how to do that.
# DIRECTORY INDEX FORCE INDEX.PHP # Use index.php as default directory index file # index.html will be ignored will not load. DirectoryIndex index.php index.html /index.php