[postcd]

Originally Posted by Lynne

Then I suggest you ask your host about why those files are forbidden suddenly.

Thank You Lynne, i followed Your advice and this is what i got from my hosting provider:

You receive 'Access Denied' page, but it is not '403 Access denied' error page, it is a proper page with '200 OK' server message.
Access must be denied on a CMS level somewhere.

We took our time to investigate the issue, but did not succeed as well.
Actions we tried:

-Renaming .htaccess files to disable them (both in public_html folder and user folder)
-Adding 'define('DISABLE_HOOKS', true);' to config.php file
-Removing and adding privileges to edit-delete posts for admin user
-Removing and adding with ALL privileges mysql user to the database
-Disabling all active plugins
-Disabling all styles except default one.

Nothing helped, unfortunately. Though, Access Denied is not a 403 error message and this might be worth mentioning to vbulletin community at https://vborg.vbsupport.ru/showthrea...69#post2427569 , perhaps they will have further ideas.