Matlab websave uses weboptions to control HTTP behavior, including Timeout and SSL Certificate. SSL certificate checking can add security to web operations. Some systems may need environment variable SSL_CERT_FILE for Matlab’s vendored cURL.

As a last resort, certificate checking can be turned off, but this opens up code / file integrity and concomitant security issues. Instead of disabling certificate checking set environment variable SSL_CERT_FILE to the actual certificate location. This example sets reply timeout to 15 seconds and specifies custom SSL certificate location when environment variable SSL_CERT_FILE is set.

if isfile(getenv("SSL_CERT_FILE"))
  web_opts = weboptions(CertificateFilename=getenv("SSL_CERT_FILE"), Timeout=15);
else
  web_opts = weboptions(Timeout=15);
end

websave(saved_file, url, opts);

Alternative: cURL with Matlab