After installing windows update KB5031224, KB5031356, .Net Framework error pops up ask to intall .Net Framework v4.0.30319

Question

Some apps have this error and asks to install .NET Freamwork

We tried these, but all was failed.

1. Uninstall all updates
2. install NET Framework 4 (Standalone Installer) / .net framework offline installer
3. sfc /scannow
4. for %1 in (%systemroot%system32*.dll) do regsvr32 /s %1
5. add register enable .Net use OS configuration tls
6. reinstall the affected app

Answer 1

Growing frustrated with the scarce information on this unspecific error message, I decided to attempt the registry import from a machine with similar updates and .Net Framework versions as the troublemaking machine:

Open the registry editor Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\ export the registry node on the working machine (as a backup) and troublemaking machine. Delete the node on the trouble making machine (not all entries could be deleted) and import (File > Import) the keys form the functioning machine. Restart Notes:

I did not bother to compare the sets of registry entries but after the replacement. Despite my old collection of entries at was much larger, e.g. containing keys related to Microsoft Visual Studio, so far no issues.

Far from an expert, upon comparing my old and new entries using WinMerge it became apparent that especially the following keys related to version v4.0.30319 were missing: netfx-sku-entries.reg.txt

Maybe a simplistic guess which ought to be verified, but since SKU is a ‹string value that specifies the stock-keeping unit (SKU), which in turn specifies which .NET Framework release this application supports› the absence of those entries could have caused the error.

Good luck with your issue and let's hope Microsoft addresses this issue soon in a more professional way ;)

Answer 2

Here is the workaround for me:

1.export the all .NET framework register key from a good pc (the same OS), and import them into the error PC.

pls do not ask me which key caused this error....

2. Reset pc

Answer 3

Download and install .NET Framework Repair Tool.

This tool detects and tries to fix some frequently occurring issues with the setup of Microsoft .NET Framework or with updates to the Microsoft .NET Framework.

Run Command Prompt as Administrator.

In the Command Prompt window, type the following command: 
Dism /online /cleanup-image /RestoreHealth

Answer 4

Hi @Xu Tony ,

Since the problem caused by windows update, it is recommended that reporting the issue through the Feedback Hub app.
https://support.microsoft.com/en-us/windows/sen...

Also check if the following steps help.

https://answers.microsoft.com/en-us/windows/forum/all/this-application-could-not-be-started-error-when/eda8e219-d686-4940-90f1-e79377043768