UnknownShadow200

Most likely you need to install the Baltimore CyberTrust Root root SSL certificate into the System Keychain. I haven't tried myself, but one of these ways should probably work: 1. Navigating to https://www.classicube.net in Safari and trusting the certificate from there (https://help.ivanti.com/ap/help/en_US/fd/2020/Content/FileDirector/Admin/Clients/Mac_Client/Install_Root_Certificate_on_Mac.htm) 2. Manually downloading the .crt from https://www.digicert.com/kb/digicert-root-certificates.htm and then double clicking it to install the certificate (https://www.eduhk.hk/ocio/content/faq-how-add-root-certificate-mac-os-x or https://support.n4l.co.nz/s/article/Installing-an-SSL-Certificate-on-an-Apple-OS-X-Device-Manually) If that still doesn't work, then try adding https-verify=false to options.txt to disable SSL certificate validation for ClassiCube (not a great idea security wise though) As an absolute last resort, try adding to http-no-https=True to force ClassiCube to connect to classicube.net over http:// instead of https://. Keep in mind that turning on this option means your account password is transmitted over the network in plain text when you sign in.

ClassiCube relies on the SSL libraries and certificates provided by the operating system Can you please update your game to the latest dev build (Updates > Latest dev build)? I have improved the error handling so that it should include more details about the error now

Are you running in classic mode or enhanced mode? (Launcher > Options > Mode) If in enhanced mode, if in-game you go to ESC > Options > Nostalgia Options, is both 'Use CPE' and 'Use server textures' on?

Are you using macOS or Linux? If so: The error code is caused by being unable to establish a secure connection to the webserver to download the texture pack from You can add curl-verbose=true to options.txt to get more detailed information to be shown in the Terminal window If only you are unable to download the texture pack though while others can download it fine, that usually means the reason why the secure connection is failing has something to do with your computer setup (typically outdated SSL libraries or certificates)

What error message are you seeing in chat?

1. Click 3 dots in top left > More Tools > Developer Tools 2. Click Console tab 3. Reload the page 4. Copy or screenshot output from Console tab - unexpected errors should be in red

What web browser and device you are using?

Which browser are you using? Does this happen in singleplayer or multiplayer?

What operating system are you using? Are you able to play audio in other applications without any issues?