try

system-config/default.nix

@@ -1,4 +1,4 @@
-{ config, lib, pkgs, inputs, ... }: {
+{ config, lib, pkgs, inputs, modulesPath, ... }: {
 
     imports = [ 
         ./services
@@ -44,7 +44,7 @@
                                     ((builtins.readDir ./configuration).${z} == "directory") 
                                     then (import ./configuration/${z} { 
                                         config = {};
-                                        inherit lib pkgs inputs; 
+                                        inherit lib pkgs inputs modulesPath; 
                                     })
                                     else null;
                                 test = if cfg == null then false