Unable to connect to SCALE VMs via SPICE with Remmina

Apps and Virtualization
1

I’m running SCALE v25.04.2.4 and am having trouble connecting to my Debian and Fedora VMs via SPICE with Remmina. I can connect to these VMs via SPICE in the web UI, just not Remmina. When I make the Remmina connection, it immediately drops, saying “Connection to the SPICE server dropped”.

I used to have this working with a Debian 12 VM in SCALE, but sadly this VM was broken when I reinstalled TrueNAS from backup (boot drive failed).

I’m certain none of the following are issues:

  1. SPICE password: I’m copying/pasting the password from my password manager, and it works through the SPICE web UI
  2. SPICE port: I’m using the “Display Port” assigned to the VM by TrueNAS
  3. IP address: I’ve confirmed the IP address of the VM, made it static, and ensured nothing else on the network is trying to use this IP
  4. Network: My laptop and TrueNAS server are on the same switch, in the same VLAN, and can communicate directly with each other without going through my firewall

Things I’ve tried:

  1. Debian 13
  2. Debian 12
  3. Fedora 42
  4. Changing the Display Port
  5. Confirming SPICE agent is running on VM with systemctl status spice-vdagent
  6. Enabling and disabling “Ensure Display Device” in VM settings
  7. UEFI and Legacy BIOS boot methods in VM settings (I can’t get VMs to boot in Legacy BIOS mode for some reason)
  8. Different implementations of Remmina:
    1. Fedora Flatpak
    2. Fedora Flathub Flatpak
    3. Fedora RPM: Doesn’t implement SPICE

Interestingly, I can connect to my Home Assistant OS VM via SPICE with Remmina, but none of my other VMs, and I can’t figure out why.

It’s possible I’m missing some configuration in the VMs I can’t connect to, but I’m not sure what that would be because last time I had this working, I don’t recall doing anything other than the following, and it just worked, so now I’m confused:

  1. Installing Debian 12
  2. Setting up the connection in Remmina with the IP address, port, and SPICE password

I’m starting to wonder if TrueNAS broke something that’s causing this issue, which would explain why I can connect to my Home Assistant OS VM, which was created in 2024, but none of my VMs created in SCALE v25.04.

Any ideas?