Cubase plugins loading slows to a crawl after Update KB5004331

August 10, 2021-KB5004331 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10, version 2004, Windows Server, version 2004, Windows 10, version 20H2, and Windows Server, version 20H2, and Windows Version 21H1

After installing this update loading Cubase slows to a crawl. Cubase starts slowly and it appears plugins load extremely slowly, so loading a project with many plugins can take a several minutes as it loads the mixer. I verified this after loading a small project, a single new instance of REQ4 took almost 1 minute to load into the mixer channel.

I uninstalled the update and Cubase returned to normal behavior.

OS Name: Microsoft Windows 10 Pro
Version: 10.0.19043 Build 19043
System Manufacturer: Gigabyte Technology Co., Ltd.
System Model: B460MDS3H
System Type: x64-based PC
Processor Intel(R) Core™ i9-10900 CPU @ 2.80GHz, 2808 Mhz, 10 Core(s), 20 Logical Processor(s)
Installed Physical Memory (RAM) 16.0 GB
Video: NVIDIA GeForce GTX 460

You don’t say which version of windows 10 you are using?

Corrected above…

You can try uninstalling that update. I just did that on my machine running windows 10 pro 64-bit. If you’re not sure how to do it, just Google uninstall windows updates.