Hyprland service not starting

Hi, new to nix, I enabled Hyprland about a week or so ago and it worked but recently when I do a:
> nix run home-manager/master switch
Starting Home Manager activation
Activating checkFilesChanged
Activating checkLinkTargets
Activating writeBoundary
Activating installPackages
nix profile remove
warning: Use ‘nix profile list’ to see the current profile.
Activating linkGeneration
Cleaning up orphan links from /home/dougal
No change so reusing latest profile generation 81
Creating home file links in /home/dougal
Activating onFilesChange
Activating reloadSystemd
The user systemd session is degraded:
xdg-desktop-portal-hyprland.service loaded failed failed Portal service (Hyprland implementation)

1 loaded units listed.
Attempting to reload services anyway…

My config.nix:
programs.hyprland = {
enable = true;
#xwayland.enable = true;
#enableNvidiaPatches = true;
It makes not difference with or without the comments above.
Any suggestions?