beginner_x

Thanks again.
I have a feeling that I am not going to be able to resolve this problem.
Nevertheless, I did try copying the .htaccess file from /public_html/wp-content/aiowps_backups directly under public_html (ie public_html/.htaccess). The code in the .htaccess file is only two lines! (I would have thought there would be quite a lot, and that this code would have been generated by AIOWPS plugin.) the two-line code consists of:
“deny,allow
deny from all”
Anyway copying it directly under public_html resulted in my not being able to log in to the site, and the following message came up instead:

“Forbidden.
You don’t have permission to access /wp-login.php on this server.
Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request”
so I undid that action (ie pasting .htaccess file directly under public_html)

When I tried to import the AIOWPS settings that I’d saved elsewhere (and which had achieved a high score on the security strength meter) the following message came up

“Could not write to the .htaccess file. Please check the file permissions”

but when I try to change file permission for aiowps_backups folder to make it writable it stubbornly refuses to change from 0755, and likewise the .htaccess file stubbornly residing within it also refuses to change from 0644 (I thought that changing it temporarily to 0777 might help). Yet any other folder within wp-contents willingly yields to having its permissions changed. I am wondering whether this might be a clue as to what could be the problem.

Next step – I will contact my host provider as per suggestion.

Thank you for reply.

I tried to apply the “solution” but it did not cure the problem.
As you know, there is a choice of six “common settings” for permalinks to choose from (by clicking anyone of the six radio buttons) beginning with the “default ” setting, and ending on the “custom structure”.
Choosing any of them except the “default” settings returns the following error message when a post or page link is clicked in the sidebar or menu bar

Not Found
The requested URL /post-3/ was not found on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request

So the page and posts links only work with “default setting as it stands, as has been the case from the beginning.

In the event that the problem were to be solved, where would it be placed by default?

(I also temporarily de-activated AIOWPS and repeated steps trying to see if it would make any difference to enable other permalinks settings to work but it made no difference)