AutoCAD 2020 Block Performance Hotfix

AutoCAD 2020 is out! Hopefully you've all had a chance to play around in it and check out the new features. As with all new things, sometimes we hit bugs. Autodesk released a Hotfix that applies to the 2020 versions of AutoCAD, AutoCAD LT, and AutoCAD 2020-based specialized toolsets. It addresses an AutoCAD performance issue when opening DWG files with large numbers of block references.

Here's how to fix it from Autodesk's Knowledge Network:

"You must have administrative privileges on your Microsoft Windows operating system to complete the installation process.
This installation requires you to replace the following files:
• accore.dll
• acdb23.dll

Download the correct Hotfix for your application to a location on your local computer:  
AutoCAD_2020_Block_Performance_Hotfix.zip, or AutoCAD_LT_2020_Block_Performance_Hotfix.zip
(This is the site to download: https://knowledge.autodesk.com/support/autocad/downloads/caas/downloads/content/autodesk-C2-AE-autocad-C2-AE-2020-block-performance-hotfix.html)
Double click on the zip file and extract the resulting files to a location on your computer, e.g. C:\Temp.

To Replace the Files  
1. Close all software applications.
2. Navigate to your product installation folder; for example, C:\Program Files\Autodesk\AutoCAD 2020.
3. In the product installation folder, right-click on the files listed below, select Properties, and go to the Details tab.  You should replace each file (following steps 4 and 5) only if the version is lower than the one listed below.
   • accore.dll 23.1.48.0
   • acdb23.dll 23.1.48.0
4. In the product installation folder, right-click on the file to rename it (e.g. acdb23.dll to acdb23.bak). 5. Move the newly downloaded file from C:\Temp to this folder.

To Uninstall This Hotfix  
1. Delete the files that you downloaded and installed.
2. Restore the renamed file to its original name (e.g. acdb23.bak to acdb23.dll). "