Windows defender platform stuck at version 4.18.1909.6

I do currently still have an issue with my Windows Defender: it crashes when I try to open the protection history. The screen with the list of menaces is briefly displayed, but then the window closes abruptly and I think the service restarts. Any tips for this one?

EDIT:

I can see there's stuff here

C:\ProgramData\Microsoft\Windows Defender\Scans\History\Service\DetectionHistory

And I can see what stuff is there with

C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0\MpCmdRun.exe -Restore -ListAll

I solved the Defender Update issues, as well as the yellow mark on the Defender icon in the taskbar

with the following simple step.

I just installed a full-blown anti virus solution. In my case (as the Windows 11 version is the 64-bit Arm based processor)

I took the Panda Dome solution. (Other major brands do not support Arm based systems).

After that the Defender updates were installed fully automatically and the yellow signal also disappeared.

All follow up Windows Updates also installed correctly from then on.

Cheers,

Guido

Sir, you are a savior!

I couldn't move the files to the C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0 folder while the system was running, even if the antimalware service was stopped and I was running explorer as TrustedInstaller.

I'll summarize the solution here for anyone with the same issue (if I understand it correctly):

The older version of Windows Defender shipped with Win10 21H1 and 21H2 was in "C:\Program Files\Windows Defender". Due to anti-tamper protection (which is active even if disabled from the Windows Defender settings, somehow) it's not possible to update the registry keys that point to the new version (installed via Microsoft Update Catalog or Windows Update, if yours works) so it's necessary to authenticate as TrustedInstaller and update the registry keys.

• The latest Anti-malware platform can be downloaded from https://www.catalog.update.microsoft.com/Search.aspx?q=KB4052623 (pick the one for your architecture, amd64 / x86 / arm).
• Run the "updateplatform_*.exe" program and wait for a good couple of minutes for it to be unpacked and installed in "C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0"

If you see this in the future, it's likely the platform was updated again and there will be different numbers. Where you see "4.18.2210.4-0", replace with the latest platform version listed here: https://www.microsoft.com/en-us/wdsi/defenderupdates

If not all of the files are moved, you will need to reboot into Safe Mode, extract the content of the .exe with 7zip or similar software and move it to "C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0" manually!

• Open the RegEdit as TrustedInstaller. There are different ways to do so, but the program https://winaero.com/execti/  suggested by _AW_ works perfectly.
• From the registry editor change the following keys:

In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender , "InstallLocation" should point to "C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0"

In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinDefend , ImagePath should point to "C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0\MsMpEng.exe"

Last thing (which helped for me but I'm not sure if it's applicable): check if the Environment Variable %ProgramData% correctly points to C:\ProgramData.

Thank to everybody for their contribution! My Windows Defender was stuck at the same version for over a year now :)

Download the engine update from:

https://www.catalog.update.microsoft.com/Search.aspx?q=KB4052623

It's the top Download, then from the three options that come up you need: updateplatform_c7e5f94329ce9c9082b974411f11b90556e443af.exe

If double clicking updateplatform_c7e5f94329ce9c9082b974411f11b90556e443af.exe doesn't install to

C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0 then you'll have to manually install it.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender - InstallLocation should point to

C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0

To manually install updateplatform_c7e5f94329ce9c9082b974411f11b90556e443af.exe you need something like 7-Zip to extract the contained archive content to a folder, then rename the folder 4.18.2210.4-0

Then you boot into safe mode and copy the folder to C:\ProgramData\Microsoft\Windows Defender\Platform

Restart the computer and the service should run.

Hello,

I just downloaded the latest Defender Antivirus and Network Real-Time inspection from https://www.microsoft.com/en-us/wdsi/defenderupdates 

I now have the folder "C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0" with the appropriate files in it.

Now I'm trying to change the ImagePath key from "%ProgramFiles%\Windows Defender\MsMpEng.exe" to "C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0\MsMpEng.exe" while authenticated as TrustedInstaller.

I could do this successfully! Is there anything else I should change? Will I have to manually update the path for every platform update? Do I need to change anything in "Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender"? The InstallLocation there still points to "C:\ProgramFiles\Windows Defender".

Thank you for your help so far!

EDIT1: after a reboot, Defender seems to be stuck here:

And everything else seems to have reset:

Platform is still 4.18.1909.6 even after changing the ImagePath and rebooting and overall it seems a bit broken, I can't activate real time protection!
If I click on the "real time protection disabled prompt" I get this message:

"Page not available, the IT Admin limited the access to some areas of the app..."

And this is all because I noticed that the folder doesn't contain any executables!
"C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2210.4-0"

Welp

EDIT2: Also downloaded and ran https://www.catalog.update.microsoft.com/Search.aspx?q=KB4052623 for 64bit Windows, doesn't appear to have made any difference to the content of that folder. Any suggestions on how to reset Windows Defender and install it cleanly from scratch is welcome!