add April non-security update release notes

docs/framework/release-notes/2025/04-22-april-cumulative-update-preview.md

@@ -0,0 +1,47 @@
+---
+title: April 2025 cumulative update preview
+description: Learn about the improvements in the .NET Framework April 2025 cumulative update preview.
+ms.date: 04/22/2025
+---
+# April 2025 cumulative update preview
+
+_Released April 22, 2025_
+
+## Summary of what's new in this release
+
+- [Security improvements](#security-improvements)
+- [Quality and reliability improvements](#quality-and-reliability-improvements)
+
+### Security improvements
+
+There are no new security improvements in this release. This update is cumulative and contains all previously released security improvements.
+
+### Quality and reliability improvements
+
+#### .NET Libraries
+
+Addresses an issue with concurrency in TypeDescriptor.GetConverter()issue in TypeDescriptor GetProperties() and GetConverter(). (*Applies to: .NET Framework 4.8, 4.8.1*)
+
+#### .NET Runtime
+
+Addresses an issue where interactions between .NET Framework DLL loads and OS code integrity enforcement policy trigger error reporting dialog boxes. (*Applies to: .NET Framework 4.8, 4.8.1*)
+
+## Known issues in this release
+
+This release contains no known issues.
+
+## Summary tables
+
+The following table outlines the updates in this release.
+
+| Product version | Cumulative update preview |
+| --- | --- |
+| **Windows 11, version 24H2** | |
+| .NET Framework 3.5, 4.8.1 | [5056579](https://support.microsoft.com/kb/5056579) |
+| **Windows 11, version 22H2 and Windows 11, version 23H2** | |
+| .NET Framework 3.5, 4.8.1 | [5056580](https://support.microsoft.com/kb/5056580) |
+| **Windows 10, version 22H2** | **[5057056](https://support.microsoft.com/kb/5057056)** |
+| .NET Framework 3.5, 4.8 | [5056577](https://support.microsoft.com/kb/5056577) |
+| .NET Framework 3.5, 4.8.1 | [5056578](https://support.microsoft.com/kb/5056578) |
+
+The operating system row lists a KB that's used for update offering purposes. When the operating system KB is offered, the applicability logic determines the specific .NET Framework update(s) installed. Updates for individual .NET Framework versions are installed based on the version of .NET Framework that is already present on the device. Because of this, the operating system KB is not expected to be listed as installed updates on the device. The expected updates installed are the .NET Framework-specific version updates listed in the previous table.

docs/framework/release-notes/release-notes.md

@@ -11,7 +11,8 @@ The .NET Framework updates include cumulative security and reliability improveme
 
 .NET Framework cumulative update releases are discussed in detail in the following individual release notes:
 
-* April 8, 2025 - [cumulative update](./2025/04-08-april-cumulative-update.md) **New Release**
+* April 22, 2025 - [cumulative update preview](./2025/04-22-april-cumulative-update-preview.md) **New Release**
+* April 8, 2025 - [cumulative update](./2025/04-08-april-cumulative-update.md)
 * March 25, 2025 - [cumulative update preview](./2025/03-25-march-cumulative-update-preview.md)
 * January 28, 2025 - [cumulative update preview](./2025/01-28-january-cumulative-update-preview.md)
 * January 14, 2025 - [cumulative update](./2025/01-14-january-cumulative-update.md)

docs/framework/toc.yml

@@ -695,6 +695,8 @@ items:
       href: release-notes/2025/03-25-march-cumulative-update-preview.md
     - name: April 2025 cumulative update
       href: release-notes/2025/04-08-april-cumulative-update.md
+    - name: April 2025 cumulative update preview
+      href: release-notes/2025/04-22-april-cumulative-update-preview.md
   - name: What's new
     href: whats-new/index.md
   - name: What's new in accessibility