First I have to say I do not use AutoCAD.
The currently available release on the web site is 201204.
See
https://web.carlsonsw.com/files/updates ... ct=CarlsonI would download the update file directly to the local drive and run as administrator or whatever your privileged user name is. If that doesn't work then download the full installer for the lates release and install it.
If you see the 200918 release as installed after the update then it would appear something with the update is not working out.
Greg