Troubleshooting "Set PluginClassLoader as Parallel Capable"

If you're receiving the error Set PluginClassLoader as parallel capable and your server isn't starting, this would suggest you have installed a plugin from an untrusted source. Nulled, cracked, or pirated software very often contains back-doors or malicious code that can cause damage to your server. Installing software from untrusted sources is never recommended and is very risky.

If you are receiving this error, removing any plugins that weren't downloaded from an official source like Modrinth, Spigot, or BukkitDev should resolve your issue. If you're not sure which plugin is causing the issue, you can disable or delete plugins one by one until you find the plugin causing the issue.