Handshake error when trying to change the wallpaper

[LinkedFluuuush]

Hello :)

I am using hyprland and hyprpaper on NixOS, and since updating to the latest hyprpaper / hyprland versions, I can no longer change my wallpaper by using hyprctl.

When running the following command :

hyprctl hyprpaper wallpaper "DP-2, /etc/nixos/backgrounds/main/Japanese Cloud City.jpg"

I get the following error:

[hw] err: server at fd 3 core protocol error: invalid message recvd (invalid type code)
[hw] err: handshake error: timed out
error: can't send: wire handshake failed

System info:

hyprland --version
Hyprland 0.52.0 built from branch unknown at commit 6175ecd4c4ba817c4620f66a75e1e11da7c7a8ca dirty (unknown).
Date: 2025-12-18
Tag: v0.52.0, commits: 0

Libraries:
Hyprgraphics: built against 0.4.0, system has unknown
Hyprutils: built against 0.11.0, system has unknown
Hyprcursor: built against 0.1.13, system has unknown
Hyprlang: built against 0.6.7, system has unknown
Aquamarine: built against 0.10.0, system has unknown

Version ABI string: 6175ecd4c4ba817c4620f66a75e1e11da7c7a8ca_aq_0.10_hu_0.11_hg_0.4_hc_0.1_hlg_0.6
flags set:
nix

hyprpaper --version
[LOG] Welcome to hyprpaper!
built from commit v0.7.6 ()

Nix config :

Flake inputs

    hyprland.url = "github:hyprwm/Hyprland";

configuration.nix

  # Enable Hyprland
  programs.hyprland = {
    enable = true;
    xwayland.enable = true;
    package =
      inputs.hyprland.packages.${pkgs.stdenv.hostPlatform.system}.hyprland;
    # make sure to also set the portal package, so that they are in sync
    portalPackage =
      inputs.hyprland.packages.${pkgs.stdenv.hostPlatform.system}.xdg-desktop-portal-hyprland;
  };

homenix

  services.hyprpaper = {
    enable = true;
    settings = {
      ipc = true;
      splash = false;
      preload = [ "/etc/nixos/backgrounds/main/Japanese Cloud City.jpg" ];
      wallpaper =
        [ "DP-2,/etc/nixos/backgrounds/main/Japanese Cloud City.jpg" ];
    };
  };