Problems with antimalware defender update 4.18.2202.4

Sometimes just booting to safe mode for a few minutes then booting back to normal mode fixes things. Won't do any harm anyway.

Fabler2 said:

Sometimes just booting to safe mode for a few minutes then booting back to normal mode fixes things. Won't do any harm anyway.

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I will give that a try.

The sound card it is not the problem i test it.
I couldn't downgrade because i can only make a clean install without keeping my files.
Please consider also to tell about the problem with feedback hub like me.

Also change the header to :
problems with antimalware defender update 4.18.2202.4 from unxplained problem!!

@BrianInEngland you have English windows?

boombastik said:

@BrianInEngland you have English windows?

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Yes, English UK

Hello, im new to the forum.
Been searching the internet all day for this.
Im having the same exact problem and i first i thought it was a malaware that spreaded in my local network.
Then i started formating my pc-s.
I tested on the first by installing windows 10 and all the latest updates included 4.18.2202.4 and no problems there but i didn’t test it long there.
Then i installed windows 11 fresh and clean on both pc after update they started to have the same problem. Updated one to the beta channel .588 same thing. Tested on macbook vm windows 11 same problem.
Can confirm by disabling all things in defender for me fixes it.
I am testing it by running sfc /scannow when defender is enabled it gets stuck at 4% or 33%. Not to mention many programs not launching.

I have 5 pc in my home three with windows 10 and two with windows 11.
Both two windows 11 machines have this problem.
@MasterDingo if you want to run sfc successfully you need to restart you machine disable all option to defender and the ran sfc.
But i have already test all these tests and more complicated ones with no success.
please use your feedback hub to report it to microsoft.

Also fill your pc specification maybe it helps me to see some pattern.

*In ms config services do you have PnkBstra service running?


One case to someone see if he/she is affected by this problem with defender is to restart the pc and then to try to open cmd. It will fail.

BrianInEngland said:

Went to the Event viewer to see what happened - Event viewer wouldn't load, it was just the circle going round. Closed Event viewer, tried again, there was a message 'waiting for all snap-ins to load'. Nothing happened after that....

....At first we thought it may be the new AMD chipset driver, we've both rolled back to the previous one but the problem hasn't gone away.
The only other explanation is an issue with the AnitMalware platform update yesterday. The problem started after that was installed.

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I'm not experiencing that.



My AMD-based System One below got the Antimalware platform update yesterday, as you can see in my (working) Event Viewer.

@Bree to see if you are affected you need to restart and try to open cmd.
Also can you test your system two if it is affected?

boombastik said:

@Bree to see if you are affected you need to restart and try to open cmd.

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Just restarted at at 17:42, as you can see in my Event Viewer, cmd still opens. I did notice however that it took longer than usual until I got to a fully working Desktop, or could open cmd. However, once settled down everything seems to work normally.

boombastik said:

I have 5 pc in my home three with windows 10 and two with windows 11.
Both two windows 11 machines have this problem.
@MasterDingo if you want to run sfc successfully you need to restart you machine disable all option to defender and the ran sfc.
But i have already test all these tests and more complicated ones with no success.
please use your feedback hub to report it to microsoft.

Also fill your pc specification maybe it helps me to see some pattern.

*In ms config services do you have PnkBstra service running?


One case to someone see if he/she is affected by this problem with defender is to restart the pc and then to try to open cmd. It will fail.

Click to expand...

I don't think there is a pattern except the Defender update. As i told you i am testing this in 3 machines with latest W11 updates and all have same problem. 2 of them i just formated and have fresh windows install.
My cmd opens normally. I tested again sfc /scannow and as soon as i disable defender and reboot the pc it works fine, also all programs start to work normally.
No PnkBstra since this are fresh installs.
Also my event viewer opens

@Bree so it seems that you are affected because mine open after 15 minute if i run cmd and leave the pc alone and then it works, but if i try to open for example harddisk sentinel before i see the cmd panel it freezes.

boombastik said:

@Bree so it seems that you are affected because mine open after 15 minute....

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Yes, it seems that I am affected after all.

The 10-15 minutes for it to settle down and work as normal seem to be due to there being a couple of cmd windows (for some system drivers) that run at each restart. Until those have run successfully no other cmd can be run. It's the first run of a cmd window after a restart that seems to take its time, but thereafter there are no issues.

As I hibernate this machine when not in use it shouldn't be an issue for now. Let's hope my next restart is for a CU that addresses this issue

I updated to the newest amd chipset this morning and ended up checking if my event viewer was working because someone in a thread on reddit for the chipset said it broke that and other things even after they uninstalled it.

I'm not sure if the chipset was the cause or not as I don't remember the last time I ended up checking my event viewer but I am having the same issue as it wont load it and it will end up giving me a snap in error but cmd is working fine after rebooting.

boombastik said:

@Bree to see if you are affected you need to restart and try to open cmd.
Also can you test your system two if it is affected?

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My System Two is an unsupported device, but my System Three (for details look at my 'Other Info' section). Is a supported Intel based device.

I have just restarted that and can open a cmd windows as soon as the desktop appears, so this seems to be an AMD-specific issue.

@Bree My systems are both intel and they are affected, but both use uefi boot (system haswell and sandybridge)
Your system three use uefi?

boombastik said:

@Bree My systems are both intel and they are affected, but both use uefi boot (system haswell and sandybridge)
Your system three use uefi?

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Yes, my System Three is a fully supported device with a 10th gen i7, using UEFI/GPT/Secure Boot/TPM 2.0 and had a clean install of Windows 11 Pro on 11th October 2021. Cmd can open straight away after a restart.

My System Two is an unsupported 1st gen i5 with a Legacy bios and an MBR install. This one was upgraded from 10 to 11 using a workaround. As it happens, when I just woke it from hibernation the 4.18.2202.4 platform update had not yet been installed.



So before installing it I tried a restart, cmd opened as normal. Then I let it install the platform update.



After a restart cmd still opens normally, so System Two isn't affected either.

My only affected machine is my System One with its AMD Athlon Silver 3050U, UEFI/GPT/Secure boot/TPM 2.0. Windows Update upgraded it from 10 to 11 on 20th October.

boombastik said:

My systems are both intel and they are affected...

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I note that while your System One's cpu is Intel, your graphics is AMD Radeon-based. This may be relevant, all my unaffected Intel systems are using Intel HD graphics.

My second machine is a laptop lenovo t420 that is affected. It had intel hd3000 gpu.
There exist an option to downgrade the antivirus platform?

I too am affected with this issue, been fighting it for several days now. I agree with some comments that this issue with the EventViewer, or using Computer Management it stalls, hangs, have to re-boot, then sometimes it will start working.

I am strongly thinking that it was the Defender Platform update that broke things. Any ideas how to get MS to get busy on a 'fix' ?