f2bmng failed: Service fail2ban doesn't exists

I use Fail2ban for a couple of years ago. I need it as breathing, I receive hundreds of attacks per second in my server .

This night the service failed. There was no way to start, and eventually tried to uninstall it, then reinstall it from the web service. Then, I took hours following tutorials and solutions found in this forum, or the official help of Plesk, without success. The errors giving me are:



If I try to activate the service in the config tab:


"Error: No se ha podido...

f2bmng failed: Service fail2ban doesn't exists