Solved Windows Defender is blocking imageres.dll

Just recently Windows Defender started blocking imageres.dll on my computer.

I've lost all of the icons on my desktop, although all of the shortcuts are still there.

If I right click on the desktop, I get a notification about Defender blocking an action and waiting about 15 to 20 seconds before the context menu appears.

If I try to open File Explorer, again Defender blocks imageres.dll and after a wait Explorer only partially appears.

If I disable Defender, everything returns to normal.

Can anyone offer any help about how to handle this?

Web search reveals: - "imageres.dll is a Windows Image Resource file developed by Microsoft Corporation as part of the Windows operating system."
Also, "Security: Verified as digitally signed by Microsoft with 0 detections on VirusTotal (as of latest scan)."

These suggest to me that Defender has detected the file as unsigned or corrupt. You haven't downloaded it from a 3rd party site have you?

If not then try running sfc /scannow in a command or power shell window.

Make sure you have no corrupt system files that is causing this problem. Open a command prompt as administrator and type dism /online /cleanup-image /restorehealth
When complete, restart. Then open command prompt as admin again and run sfc /scannow
Pay attention to the scan results to see if SFC found anything it could not repair. If it did find and repair something, restart again.

Make sure you have the latest Defender definitions.
Settings>Privacy & Security>Windows Security>Virus&Threat Protection>Virus & Threat Protection Updates>Protection Updates>Check for Updates

Go to: Windows Security → Virus & threat protection → Protection history, Is anything in there that points to C:\Windows\System32 directory, If so what is the exact detection name and what action did Defender take.

I tried all that, including an offline scan, with no success.

After a Google search I found that if I go to Settings>System>System Components>Windows Security I can choose Advanced Options. In there are options to repair or reset Windows defender.

This seems to have worked for me.