diff --git a/src/renderer/src/components/Settings/PaintScale/usePaintScaleConfig.ts b/src/renderer/src/components/Settings/PaintScale/usePaintScaleConfig.ts
index 64462e7..a79bf0d 100644
--- a/src/renderer/src/components/Settings/PaintScale/usePaintScaleConfig.ts
+++ b/src/renderer/src/components/Settings/PaintScale/usePaintScaleConfig.ts
@@ -1,11 +1,14 @@
 import { useState, useEffect } from 'react';
 import ipcTypes from '../../../../../util/ipcTypes.json';
-import {PaintScaleConfig, PaintScaleType} from "./types";
+import { PaintScaleConfig, PaintScaleType } from "./types";
+import { message } from "antd";
+import {useTranslation} from "react-i18next";
 
 type ConfigType = 'input' | 'output';
 
 export const usePaintScaleConfig = (configType: ConfigType) => {
   const [paintScaleConfigs, setPaintScaleConfigs] = useState<PaintScaleConfig[]>([]);
+  const { t } = useTranslation();
 
   // Get the appropriate IPC methods based on config type
   const getConfigsMethod = configType === 'input'
@@ -55,6 +58,20 @@ export const usePaintScaleConfig = (configType: ConfigType) => {
         });
   };
 
+  // New helper to check if a path is unique across input and output configs
+  const checkPathUnique = async (newPath: string): Promise<boolean> => {
+    try {
+      const inputConfigs: PaintScaleConfig[] = await window.electron.ipcRenderer.invoke(ipcTypes.toMain.settings.paintScale.getInputConfigs);
+      const outputConfigs: PaintScaleConfig[] = await window.electron.ipcRenderer.invoke(ipcTypes.toMain.settings.paintScale.getOutputConfigs);
+      const allConfigs = [...inputConfigs, ...outputConfigs];
+      // Allow updating the current config even if its current value equals newPath.
+      return !allConfigs.some(config => config.path === newPath);
+    } catch (error) {
+      console.error("Failed to check unique path:", error);
+      return false;
+    }
+  };
+
   // Handle adding a new paint scale config
   const handleAddConfig = (type: PaintScaleType) => {
     const newConfig: PaintScaleConfig = {
@@ -75,22 +92,25 @@ export const usePaintScaleConfig = (configType: ConfigType) => {
     saveConfigs(updatedConfigs);
   };
 
-  // Handle path selection
-  const handlePathChange = (id: string) => {
-    window.electron.ipcRenderer
-        .invoke(setPathMethod, id)
-        .then((path: string | null) => {
-          if (path) {
-            const updatedConfigs = paintScaleConfigs.map((config) =>
-                config.id === id ? { ...config, path } : config,
-            );
-            setPaintScaleConfigs(updatedConfigs);
-            saveConfigs(updatedConfigs);
-          }
-        })
-        .catch((error) => {
-          console.error(`Failed to set paint scale ${configType} path:`, error);
-        });
+  // Handle path selection (modified to check directory uniqueness)
+  const handlePathChange = async (id: string) => {
+    try {
+      const path: string | null = await window.electron.ipcRenderer.invoke(setPathMethod, id);
+      if (path) {
+        const isUnique = await checkPathUnique(path);
+        if (!isUnique) {
+          message.error(t("settings.errors.duplicatePath"));
+          return;
+        }
+        const updatedConfigs = paintScaleConfigs.map((config) =>
+          config.id === id ? { ...config, path } : config,
+        );
+        setPaintScaleConfigs(updatedConfigs);
+        saveConfigs(updatedConfigs);
+      }
+    } catch (error) {
+      console.error(`Failed to set paint scale ${configType} path:`, error);
+    }
   };
 
   // Handle polling interval change
@@ -109,4 +129,4 @@ export const usePaintScaleConfig = (configType: ConfigType) => {
     handlePathChange,
     handlePollingIntervalChange,
   };
-};
\ No newline at end of file
+};
diff --git a/src/util/translations/en-US/renderer.json b/src/util/translations/en-US/renderer.json
index f86bf3a..50d631c 100644
--- a/src/util/translations/en-US/renderer.json
+++ b/src/util/translations/en-US/renderer.json
@@ -25,6 +25,9 @@
 				"startwatcher": "Start Watcher",
 				"stopwatcher": "Stop Watcher\n"
 			},
+			"errors": {
+				"duplicatePath": "The selected directory is already used in another configuration."
+			},
 			"labels": {
 				"emsOutFilePath": "EMS Out File Path (Parts Order,  etc.)",
 				"pollinginterval": "Polling Interval (ms)",