I am unable to download and install the ColdFusion2023 updates from update 6 for local developer version.

Update 19 of ColdFusion 2023 is out today. Consequently, I have updated this post from Update 18 to Update 19. I also corrected some typos.

What happens when you attempt to install Update 19 manually? For example, by following the instructions for Update 19 at https://helpx.adobe.com/coldfusion/kb/coldfusion-2023-update-19.html :

1. Stop ColdFusion 2023.
2. Delete all the contents of C:\ColdFusion2023\bundles (I have assumed that that is your bundles path).
3. Download packages.zip. Unzip it and move all of the contents (repo, updateinstallers, adminapi-2023.0.0.330468.jar, … ) to C:\ColdFusion2023\bundles.
   Confirm that the Update 19 Jar file is located at C:\ColdFusion2023\bundles\updateinstallers\hotfix-019-330899.jar.
4. Open the CMD prompt as administrator. Use cd to navigate to the bin directory of the Java installation that ColdFusion runs on. For example, C:\ColdFusion2023\jre\bin. 
5. Run the DOS command: C:\ColdFusion2023\jre\bin\java.exe -jar C:\ColdFusion2023\bundles\updateinstallers\hotfix-019-330899.jar

Post in the ColdFusion forum (change title slightly to avoid a duplicate post error):

https://community.adobe.com/coldfusion-580