Help with installing OPPM

[SORI_BUG 0]

I just set up a tier2 computer case on my survival world and got everything inside, computer launches normally etc, but when i run the install oppm thing it just says "could not connect to the internet. Please ensure you have an internet connection. Unable to connect to the internet. " and then it says "package does not exist." I have not found anything on how to solve this and this does not even happen in oppm install tutorials ive watched, help please? I am on the Dungeons Dragons and Space Shuttles modpack on mc 1.12.2

[.theros 0]

Do you have an internet card?

[feldim2425 8]

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Because OC is on 1.12.2 and that Minecraft version uses Java 8 the cacerts file is outdated.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>