Try this:
- Download the OpenSSL artifact using your browser
- Extract the contents twice, e.g. using 7-zip
- Create a new folder in
C:\Users\NAMENAME\.julia\artifacts
, and name it8b5673894767bc39a7d0dfdad9c9c083fd9fe304
- Copy the three folders
bin
,include
, andshare
from the extracted folder to the new folder - Run
julia>]add HTTP
again