you could make an installer that pulls it from github

This issue is likely caused because of a issue that was already discussed here are a few links: https://github.com/MightyPirates/OpenComputers/issues/3696 https://github.com/MightyPirates/OpenComputers/issues/3717 https://www.reddit.com/r/OpenComputers/comments/1d7xrsu/oppm_wont_install_even_with_network_card_inserted/ Because OC is on 1.12.2 and that Minecraft version uses Java 8 the cacerts file is outdated. This causes all TLS connections that depend on newer root certificates to fail. The Minecraft Launcher comes with it's own version of Java so would recommend installing Java on your own (Either OpenJDK based Adoptium or the official version)  and use that instead of whatever ships with the Launcher. Alternatively you can replace the cacerts file which is placed in the `lib/security` directory inside the java path. The official Minecraft launcher puts the java runtime into `.minecraft/runtime/jre-legacy/<os>/jre-legacy` the new version of the cacerts file can be found by simply downloading the ZIP version of the Adoptium JRE and taking the file from `lib/security/cacerts`. Or if you don't want to replace the file you can save it somewhere and add a JVM parameter to your launcher: -Djavax.net.ssl.trustStore=<path_to_cacerts>

Ohh, I forgot to mention, it will be on github as a zip folder which's contents you can add to a specified filesystem folder in your savegame

it seems i cant install it

I might be a bit late to this, but you can look at how i did it, thought this has no actual "button", its just clickable text.