Thanks
The Audit Log Viewer is now working again. I don’t know what happened. There is almost nothing that I actively did.
I am using also another similar plugin, Better WP Security, but I’m not so sure there was a possible conflict, because I already tried to disable it when I was looking for a solution. One thing that I did with this other plugin was enabling the setting “Disable login error messages”.
Regarding your last sentence, I was not referring to an upgrade but to a clean re-installation of the plugin, and as I said all the previous logs were maintained.
Let’s see how it goes now.
