openSUSE TW Nagios - Access forbidden!


A few days ago I have done the latest updates to my openSUSE Tumbleweed server in which I run Nagios.
The updates finished without any error and from that time when I try to login to nagios, I see the login windows, I am using my credentials and the next screen is

Access forbidden!
You don't have permission to access the requested directory. There is either no index document or the directory is read-protected.

If you think this is a server error, please contact the webmaster.

Error 403

apache and nagios services are enabled and started
any ideas?

Might review this:

I had already checked most of “Reasons” from the link and now check all the others.
Nothing yet