Product Stocking Failes Updating

I don't know what happend and i haven't done anything with the store, but suddenly i get a "error 404 site can't be found" every time I try to change the number of items i have left of a product. This happens when i try to change it in the product itself. I also get the same error if the product have options/alternativs and if I try to deactivate the options/alternativ and also if I try to deactivate the product itself

Its really frustrating for I cant set 0 sold out on products

I was hoping this was temperarly but it has been this way for 3 days.

I have version 4.3.9

Please check if the mod_security module is enabled on the server and try disabling it

Please check if the mod_security module is enabled on the server and try disabling it

ok were do I find this? via phpadmin?

Use the following URL in the admin panel:

admin.php?dispatch=tools.phpinfo

Iam sorry, but were? Could you please explain in more detail?

Administration->Logs->Gear icon->PHP information

Iam sorry, but were? Could you please explain in more detail?

Log in admin panel. For example, in the address bar on the home page you see

https://mydomain.com/admin.php

Then use

https://mydomain.com/admin.php?dispatch=tools.phpinfo