SharePoint server 2016 - Pbm installing KB4565511 : is KB890830 the root of my issue?

Question

I don't know if the two issues I have are related and if the right solution is to uninstall and block Microsoft Removal Tools update KB890830, but here we go :

My environment: SharePoint enterprise Server 2016 x64, installed on Windows Server 2016 Standard x64. I have a farm of 4 main servers :

• 1 Front-End Server (web1)
• 1 Applicatif Server (app1)
• 1 SQL Server (sql)
• 1 search server (search)

This farm is up-to-date except for the latest CU from July 2020.

The issues I have :

1] I have a problem installing 2020-07 Cumulative Update for Windows Server 2016 (KB4565511).

I tried to install it back in mid-July 2020, while I updated other KB :

• KB4475594 (Security Update for SP Enterprise Server 2016 farm deployment)
• KB890830 (Windows Malicious Software Removal Tools x64 V5.82)

The two KB above installed successfully, even i I had to run the updates several times to make it work. The CU is not installing, it fails everytime.

2] I have a random problem with File Explorer when using SharePoint

For the details of this issue, please see my post on upload through File Explorer randomly impossible here. Strangely, this issue has happened (randomly) ever since I have updated my servers.

The solution I found that could work :

I found by searching on the internet that the KB890830 can be the root of a lot of issues, including blocking updates :

• Issues With Update KB890830 Windows Malicious Removal Tools -From 2017, apparently the KB blocks other updates

Even if MsRT completes any other malware-searching software, it seems to run only sporadically, when the update is installed. : According to MS (in "How to remove MSRT"),

The MSRT does not use an installer. Typically, when you run the MSRT, it creates a randomly named temporary directory on the root drive of the computer. This directory contains several files, and it includes the Mrtstub.exe file. Most of the time, this folder is automatically deleted after the tool finishes running or after the next time that you start the computer. However, this folder may not always be automatically deleted. In these cases, you can manually delete this folder, and this has no adverse effect on the computer.

So, How can i uninstall MSRT (even though it is not installed)?

How can I uninstall the latest update (KB 890830) ?

Thanks a lot. If you think the root cause of my issues is not MSRT, please let me know, as I do not have a lot of knowledge about such subjects.

have a perfect day !