Can't enable .NET Environment in Windows 10 1903

I even did a Windows Reset, but the results were no better than your in-place upgrade. .NET still looks the same, with several items misplaced in the list of available Windows Features. Even MMC cannot load the Event viewer now.

That leaves a clean install as the only way forward that I can suggest.

It's certainly looking that way, Don. I'm now seeing more & more reports of this issue in the Feedback Hub too. No response from MS on any of the feedback though.

Wonder if this will end up making it through to the 1903 release & they'll end up with yet another major issue for a small percentage of users (which still adds up to a large number of people) that was reported as a serious bug in the feedback hub but never actioned?

I found this documented on the Visual Studio .NET Developer Community Forums since January, 2019 and it is the most upvoted Problem there.

https://developercommunity.visualstudio.com/content/problem/421852/windows-10-64-bit-1809-net-framework-4-and-472-can.html

Please Upvote this there also. There is a utility, Collect.exe, that can gather all of the relevant log files to attach to your Comment in this Forum.

http://aka.ms/vscollect

Use the Comment reply type there, not the Solution reply.

Same exact problem, same exact build and update .. although I went in and turned a few features back on in components, not I cant access all of my control panel...

I have a Hyper-V VM in which I have replicated this issue. I have tried Windows Reset as well as an in-place upgrade (to the same build number).  Neither one fixed it. The VM was originally a clean install of build 18362.30.  I am unable to remove the .30 CU.  It keeps upgrading itself to 18362.53, although that CU I can remove.

In my research, there seems to be some indication that adding KB updates or Language Packs when these .NET symptoms exist, may make it impossible to repair. Uninstalling the KB update or Language Pack has sometimes helped (with Servers).

So the simplest fix is a total wipe and clean install. I did not have this issue until I totally uninstalled .NET on this VM.  It is the missing Parent Features that are blocking the reinstallation of .NET Features.  The Parent Features are not the same type of Feature On Demand as what we see in the Windows Features Control Panel.

An example of one of the chains of .NET features from a working system is below.

PS C:\> Get-WindowsOptionalFeature -Online -Verbose -FeatureName NetFx4Extended-ASPNET45                                                                        VERBOSE: Target Image Version 10.0.18362.53

FeatureName      : NetFx4Extended-ASPNET45

DisplayName      : ASP.NET 4.8

Description      : ASP.NET 4.8

RestartRequired  : Possible

State            : Disabled

CustomProperties :

                   ServerComponent\Description : .NET Framework ASP.NET 4.8

                   ServerComponent\DisplayName : ASP.NET 4.8

                   ServerComponent\Id : 429

                   ServerComponent\InstallWithParentByDefault : true

                   ServerComponent\Parent : NET-Framework-45-Core

                   ServerComponent\Type : Feature

                   ServerComponent\UniqueName : NET-Framework-45-ASPNET

                   ServerComponent\NonAncestorDependencies\ServerComponent\UniqueName : NET-Framework-45-Extended

                   ServerComponent\Deploys\Update\Name : NetFx4Extended-ASPNET45

                   ServerComponent\Version\Major : 4

                   ServerComponent\Version\Minor : 5

I inadvertently upgraded to 18362 and now .NET will not start. I tried to restore to several earlier restore points and that fails also.

I tried to install Insider Preview 18885.1001 and that failed also. 

My home automation software runs on this system and needs .NET 4.0.

When is Microsoft going to resolve this issue? 

This is unacceptable. 

You can try some of the fixes that were described here in this thread. Sometimes they work.

Check if the .NET features appear as they normally do in your Control Panel Features. If so,  NET can probably be fixed using DISM or PowerShell.

Normal list is potentially repairable:                                            The appearance on the right has no known fix that I have found:

The abnormal list is displaying some sub-features of the missing top-level features. The Parent features have vanished. The Parent features also do not appear in DISM/PowerShell. Even when Disabled or DisabledWithPayloadRemoved, the Features should never vanish from the list that is displayed with DISM /Online /Get-Features /Format:Table.

In Windows Server you can eliminate all parts of .NET, but there is a command that can restore it all, as long as you can point to the matching WIM file from the Windows Server install ISO as a Source.  This same command does not exist for Windows 10 client and you can't run the command from a server to affect a Windows 10 client.  Below is the Feature list from Windows Server that names some of the .NET Features on Windows 10 that are missing on devices that have this problem.