Added About Us page, but cannot view it in WP admin or on the site

Hi all,

I uploaded a new template (Responsive) which took the place of another template I had someone on FIVVER do for me. I added an about Us page, but it does not show up when I select view in Admin nor when I view the site. I get the following when I try to view it:

“Not Found

The requested URL /blog/about-us/ was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.”

Here is the web address:

https://www.about-sports-collectibles.com/blog/

However, If I select “Default” under common settings instead of “Post Name”, I can view the page and the changes show up. Now if I go back and select “post Name” again, I get a notice in yellow at the top of the page that says “You should update your .htaccess now”. Here is my current .htaccess rules:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /blog/
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]
</IfModule>

Can anyone Please tell me what .htaccess rules I should be using and how I would go about changing them? I am new to WordPress and it has been kicking my butt most of the day trying to figure this out.

Thanks,

Don