Hello @Anonymous,
welcome to Fusion 360 Community Forum. Thanks for posting!
This is a report from "7-Zip" application. Can you clarify how it is linked to Fusion 360 / in which circumstances it appeared? Thanks in advance!
Best regards,
I get this error when starting your "Fusion 360 Client Downloader"
For refence for future instances by users. I had not used Fusion 360 in some time and had a pop up state that I needed to download an update. After downloading the update I had this similar error appear. I opened the .exe file in 7zip (my zip archiver) and extracted all the files to a folder. From there I opened the .exe in the parent folder and the update/ install started working.