diff --git a/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/CollectionValidator.cs b/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/CollectionValidator.cs
index 94979e7a3..02f32a8e6 100644
--- a/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/CollectionValidator.cs
+++ b/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/CollectionValidator.cs
@@ -5,66 +5,21 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
-using System;
-using System.Collections;
 using System.Threading.Tasks;
-using Squidex.Infrastructure.Translations;
 
 namespace Squidex.Domain.Apps.Core.ValidateContent.Validators
 {
-    public sealed class CollectionValidator : IValidator
+    public sealed class CollectionValidator : CollectionValidatorBase, IValidator
     {
-        private readonly bool isRequired;
-        private readonly int? minItems;
-        private readonly int? maxItems;
-
         public CollectionValidator(bool isRequired, int? minItems = null, int? maxItems = null)
+            : base(isRequired, minItems, maxItems)
         {
-            if (minItems.HasValue && maxItems.HasValue && minItems > maxItems)
-            {
-                throw new ArgumentException("Min length must be greater than max length.", nameof(minItems));
-            }
-
-            this.isRequired = isRequired;
-            this.minItems = minItems;
-            this.maxItems = maxItems;
         }
 
         public Task ValidateAsync(object? value, ValidationContext context, AddError addError)
         {
-            if (!(value is ICollection items) || items.Count == 0)
-            {
-                if (isRequired && !context.IsOptional)
-                {
-                    addError(context.Path, T.Get("contents.validation.required"));
-                }
-
-                return Task.CompletedTask;
-            }
-
-            if (minItems.HasValue && maxItems.HasValue)
-            {
-                if (minItems == maxItems && minItems != items.Count)
-                {
-                    addError(context.Path, T.Get("contents.validation.itemCount", new { count = minItems }));
-                }
-                else if (items.Count < minItems || items.Count > maxItems)
-                {
-                    addError(context.Path, T.Get("contents.validation.itemCountBetween", new { min = minItems, max = maxItems }));
-                }
-            }
-            else
-            {
-                if (minItems.HasValue && items.Count < minItems)
-                {
-                    addError(context.Path, T.Get("contents.validation.minItems", new { min = minItems }));
-                }
-
-                if (maxItems.HasValue && items.Count > maxItems)
-                {
-                    addError(context.Path, T.Get("contents.validation.maxItems", new { max = maxItems }));
-                }
-            }
+            ValidateRequired(value, context, addError);
+            ValidateSize(value, context, addError);
 
             return Task.CompletedTask;
         }
diff --git a/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/CollectionValidatorBase.cs b/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/CollectionValidatorBase.cs
new file mode 100644
index 000000000..c2d531fd8
--- /dev/null
+++ b/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/CollectionValidatorBase.cs
@@ -0,0 +1,86 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschränkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.Collections;
+using Squidex.Infrastructure.Translations;
+
+namespace Squidex.Domain.Apps.Core.ValidateContent.Validators
+{
+    public abstract class CollectionValidatorBase
+    {
+        private readonly bool isRequired;
+        private readonly int? minItems;
+        private readonly int? maxItems;
+
+        protected CollectionValidatorBase(bool isRequired, int? minItems = null, int? maxItems = null)
+        {
+            if (minItems.HasValue && maxItems.HasValue && minItems > maxItems)
+            {
+                throw new ArgumentException("Min length must be greater than max length.", nameof(minItems));
+            }
+
+            this.isRequired = isRequired;
+            this.minItems = minItems;
+            this.maxItems = maxItems;
+        }
+
+        protected void ValidateRequired(object? value, ValidationContext context, AddError addError)
+        {
+            var size = 0;
+
+            if (value is ICollection items)
+            {
+                size = items.Count;
+            }
+
+            if (size == 0 && isRequired && !context.IsOptional)
+            {
+                addError(context.Path, T.Get("contents.validation.required"));
+            }
+        }
+
+        protected void ValidateSize(object? value, ValidationContext context, AddError addError)
+        {
+            var size = 0;
+
+            if (value is ICollection items)
+            {
+                size = items.Count;
+            }
+
+            if (size == 0)
+            {
+                return;
+            }
+
+            if (minItems.HasValue && maxItems.HasValue)
+            {
+                if (minItems == maxItems && minItems != size)
+                {
+                    addError(context.Path, T.Get("contents.validation.itemCount", new { count = minItems }));
+                }
+                else if (size < minItems || size > maxItems)
+                {
+                    addError(context.Path, T.Get("contents.validation.itemCountBetween", new { min = minItems, max = maxItems }));
+                }
+            }
+            else
+            {
+                if (minItems.HasValue && size < minItems)
+                {
+                    addError(context.Path, T.Get("contents.validation.minItems", new { min = minItems }));
+                }
+
+                if (maxItems.HasValue && size > maxItems)
+                {
+                    addError(context.Path, T.Get("contents.validation.maxItems", new { max = maxItems }));
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/ReferencesValidator.cs b/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/ReferencesValidator.cs
index 95b5aafd1..dcb3d73a3 100644
--- a/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/ReferencesValidator.cs
+++ b/backend/src/Squidex.Domain.Apps.Core.Operations/ValidateContent/Validators/ReferencesValidator.cs
@@ -31,7 +31,7 @@ namespace Squidex.Domain.Apps.Core.ValidateContent.Validators
 
         public async Task ValidateAsync(object? value, ValidationContext context, AddError addError)
         {
-            if (value is ICollection<DomainId> contentIds)
+            if (value is ICollection<DomainId> contentIds && contentIds.Count > 0)
             {
                 var foundIds = await checkReferences(contentIds.ToHashSet());
 
diff --git a/frontend/app/shared/services/schemas.service.spec.ts b/frontend/app/shared/services/schemas.service.spec.ts
index cd62f6f03..ca8b09ea6 100644
--- a/frontend/app/shared/services/schemas.service.spec.ts
+++ b/frontend/app/shared/services/schemas.service.spec.ts
@@ -600,6 +600,19 @@ describe('SchemasService', () => {
         req.flush({});
     }));
 
+    function schemaPropertiesResponse(id: number, suffix = '') {
+        return {
+            label: `label${id}${suffix}`,
+            contentsSidebarUrl: `url/to/contents/${id}${suffix}`,
+            contentSidebarUrl: `url/to/content/${id}${suffix}`,
+            tags: [
+                `tags${id}${suffix}`
+            ],
+            validateOnPublish: id % 2 === 1,
+            hints: `hints${id}${suffix}`
+        };
+    }
+
     function schemaResponse(id: number, suffix = '') {
         return {
             id: `schema-id${id}${suffix}`,
@@ -611,15 +624,7 @@ describe('SchemasService', () => {
             createdBy: `creator${id}`,
             lastModified: `${id % 1000 + 2000}-11-11T10:10:00Z`,
             lastModifiedBy: `modifier${id}`,
-            properties: {
-                label: `label${id}${suffix}`,
-                contentsSidebarUrl: `url/to/contents/${id}${suffix}`,
-                contentSidebarUrl: `url/to/content/${id}${suffix}`,
-                tags: [
-                    `tags${id}${suffix}`
-                ],
-                hints: `hints${id}${suffix}`
-            },
+            properties: schemaPropertiesResponse(id, suffix),
             version: `${id}`,
             _links: {
                 update: { method: 'PUT', href: `/schemas/${id}` }
@@ -639,16 +644,7 @@ describe('SchemasService', () => {
             lastModified: `${id % 1000 + 2000}-11-11T10:10:00Z`,
             lastModifiedBy: `modifier${id}`,
             version: `${id}`,
-            properties: {
-                label: `label${id}${suffix}`,
-                contentsSidebarUrl: `url/to/contents/${id}${suffix}`,
-                contentSidebarUrl: `url/to/content/${id}${suffix}`,
-                validateOnPublish: id % 2 === 1,
-                tags: [
-                    `tags${id}${suffix}`
-                ],
-                hints: `hints${id}${suffix}`
-            },
+            properties: schemaPropertiesResponse(id, suffix),
             previewUrls: {
                 Default: 'url'
             },
@@ -824,7 +820,7 @@ function createSchemaProperties(id: number, suffix = '') {
         `hints${id}${suffix}`,
         `url/to/contents/${id}${suffix}`,
         `url/to/content/${id}${suffix}`,
-        id % 2 === 0,
+        id % 2 === 1,
         [
             `tags${id}${suffix}`
         ]