diff --git a/packages/core/database/src/inherited-collection.ts b/packages/core/database/src/inherited-collection.ts
index 7726dc8086..4705b2b32b 100644
--- a/packages/core/database/src/inherited-collection.ts
+++ b/packages/core/database/src/inherited-collection.ts
@@ -65,6 +65,10 @@ export class InheritedCollection extends Collection {
   parentFields() {
     const fields = new Map<string, Field>();
 
+    if (!this.parents) {
+      return fields;
+    }
+
     for (const parent of this.parents) {
       if (parent.isInherited()) {
         for (const [name, field] of (<InheritedCollection>parent).parentFields()) {
diff --git a/packages/plugins/@nocobase/plugin-file-manager/src/server/migrations/20250225225034-increase-url-length.ts b/packages/plugins/@nocobase/plugin-file-manager/src/server/migrations/20250225225034-increase-url-length.ts
index a8b4671c7d..1d76edeaa2 100644
--- a/packages/plugins/@nocobase/plugin-file-manager/src/server/migrations/20250225225034-increase-url-length.ts
+++ b/packages/plugins/@nocobase/plugin-file-manager/src/server/migrations/20250225225034-increase-url-length.ts
@@ -10,6 +10,7 @@
 import { DataTypes } from 'sequelize';
 import { Migration } from '@nocobase/server';
 import { CollectionRepository } from '@nocobase/plugin-data-source-main';
+import { InheritedCollection } from '@nocobase/database';
 
 export default class extends Migration {
   on = 'afterLoad'; // 'beforeLoad' or 'afterLoad'
@@ -31,23 +32,25 @@ export default class extends Migration {
 
     await this.db.sequelize.transaction(async (transaction) => {
       for (const collection of collections) {
-        const tableName = collection.getTableNameWithSchema();
-        await queryInterface.changeColumn(
-          tableName,
-          'url',
-          {
-            type: DataTypes.TEXT,
-          },
-          { transaction },
-        );
-        await queryInterface.changeColumn(
-          tableName,
-          'path',
-          {
-            type: DataTypes.TEXT,
-          },
-          { transaction },
-        );
+        if (!(collection instanceof InheritedCollection)) {
+          const tableName = collection.getTableNameWithSchema();
+          await queryInterface.changeColumn(
+            tableName,
+            'url',
+            {
+              type: DataTypes.TEXT,
+            },
+            { transaction },
+          );
+          await queryInterface.changeColumn(
+            tableName,
+            'path',
+            {
+              type: DataTypes.TEXT,
+            },
+            { transaction },
+          );
+        }
 
         await FieldRepo.update({
           filter: {