If you are having problems connecting to an Opal Server over https, and are getting an error message like:
Error in curl::curl_fetch_memory(url, handle = handle) :
schannel: next InitializeSecurityContext failed: SEC_E_UNTRUSTED_ROOT (0x80090325) - The certificate chain was issued by an authority that is not trusted.
this can be resolved by changing the curl backend to openssl. This can be done by calling the R function
Sys.setenv(CURL_SSL_BACKEND = "openssl") or by adding the line
CURL_SSL_BACKEND=openssl to the “.Renviron” file in your R project.