The fastest way to troubleshoot Security Craft Mod is to reduce uncertainty. Start with the exact versions, then read the first relevant loader or mod error, and change one thing at a time. Reinstalling everything at once usually hides the real cause.
Crash before the main menu
Check for a mod built for another Minecraft version, the wrong loader, a missing dependency or duplicate mod files. The first meaningful loader error often names the incompatible component.
Mod does not appear in the list
Confirm that you launched the profile whose mods folder you edited. Then verify the file is complete, the loader is active and the build supports that loader.
World crashes after an update
Stop repeatedly opening the same world. Copy the world, review the update path and test whether the old working mod set can still open the backup.
Recipes or items seem missing
Version changes or modpack recipe scripts can alter expected content. Compare your exact release and pack configuration with the guide you are following.
A disciplined test order
Test the mod with only required dependencies in a fresh profile. If that works, add the rest of the modpack back in small groups until the conflict is isolated.
Next step
When you are ready to install, return to the main Security Craft Mod download section after checking that your game version, loader and intended build match. For broader setup context, compare this guide with the installation setup guide.