Can't make a VM in virt-manager for winapps

So basically I wanna use winapps, and when I go to create a virtual machine, everything goes to plan. But when im on the last screen it says that the network is inactive, when I try to start it, it gives me the following error:

Could not start virtual network 'default': internal error: Failed to initialize a valid firewall backend.

I tried every possible solution, installing ebtables and dnsmasq, when I restart libvirtd and virt-manager it gives me the following error (with ebtables and dnsmasq installed):

Could not start virtual network 'default': internal error: Failed to apply firewall rules /usr/bin/iptables -w --table filter --list-rules: # Warning: iptables-legacy tables present, use iptables-legacy to see them iptables v1.8.7 (nf_tables): Could not fetch rule set generation id: Invalid argument

And this issue won't go away, I tried this some months ago and it was giving the same errors

Also, every time I need to run virt-manager, virsh and other KVM-related stuff with root. I don't know if this is normal behaviour or I am doing something wrong.